System and methods for assessing oral feeding skills during oral feeding

ABSTRACT

The present invention relates to systems and methods for assessing and improving an infant&#39;s oral feeding skills. The system comprises a “smart” baby feeding device comprising an instrumented baby bottle with a removable, battery-powered monitoring module wirelessly connected to a remote device (e.g., smart phone, tablet, laptop, PC). The purpose of the remote device is to monitor (in real time) and measure the frequency and quality of feedings of new-born babies to help optimize feeding development by providing real-time feeding performance information back to the caregiver. The information collected is of assistance in minimizing feeding difficulties and correcting feeding deficiencies.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made, in part, with US government support under agrant from the National Institute of Child Health and Human Development(R01-HD044469). The US government has certain rights in the invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION Field of the Invention

This invention pertains to the oral feeding of all infants, be they bornterm or preterm, when bottle- and breast-fed.

Description of Related Art

There are no well-defined objective means to identify the level of oralfeeding skills (OFS) in newborn infants, be they born prematurely or atterm. Assessing infants' oral feeding skills is difficult due to thelack of well-defined outcomes and available technology. The main dilemmathat caregivers face when addressing oral feeding difficulties pertainsto an infant's ability to complete his/her feedings safely andefficiently. Term infants are expected to feed by mouth readily.However, some of them do encounter oral feeding difficulties, be itbreast or bottle, which lead their caregivers to seek medical advices,e.g., pediatricians, feeding therapists, feeding disorders clinics. Theexistence of bottle feeding difficulties is reflected by the existenceof ‘special’ bottles in the general marketplace labeled as reducing‘colic’, closest to mother's breast, etc.

For infants born prematurely in hospitals, bottle-feeding is a morecomplex problem. Due to their immaturity, they are generally tube-fed atfirst. They are transitioned to oral feeding at a later time when theiroral feeding skills are believed to be adequate to ensure safety andcompetency. Attainment of independent oral feeding being one of thecriteria recommended by the American Academy of Pediatrics for hospitaldischarge [1], their inability to feed by mouth safely and competentlywill understandably delay their hospital discharge and mother-infantreunification, while increasing medical cost and maternal stress [2, 3].For all infants who demonstrate oral feeding difficulties, be they termor preterm, it is difficult to identify the causes for such difficultiesdue to the lack of evidence-based objective tool(s) that assesses theiroral feeding skills.

A variety of descriptive and objective scales for both categories ofinfants have been developed. A descriptive scale uses sensory, e.g.,visual, and behavioral observations to assess the appropriateness oforal feeding skills, e.g., the Neonatal Oral-Motor Assessment Scale(NOMAS) developed by Palmer; and the Early Feeding Skill assessment(EFS) by Thoyre, et. al [4, 5]. The accuracy of this type of approachhas been debated due to their subjective nature and lack of directmeasure of objective outcomes. Multidisciplinary assessments of aninfant's potential ability to oral feed are used on the basis that itwould be more accurate if feedback from the varied caregivers involvedin his/her care were taken into account [9, 10]. For instance, Als [8]has recommended the use of a developmental care approach incorporatingfeedback from the different members of an infant's caregivers' teamwould optimize infant's oral feeding on the basis that if an infant'sclinical stability, organization, and competence could be enhanced,his/her physiologic and behavioral expression would be optimized.

More objective and quantitative evaluations of oral feeding skills areillustrated by tools that have been developed to measure outcomes, suchas: nutritive and nonnutritive sucking patterns and their rhythmicity,sucking force, and coordination of suck-swallow-respiration, andesophageal function [11-15, 30]. However, these approaches necessitatethe use of specialized research equipment not readily available tohealth professionals. Therefore, due to the difficulty in identifyingthe maturity level of infant oral feeding skills (OFS), oral feedingassessments remain in the hands of caregivers, feeding therapists andphysicians who rely primarily on subjective scales, many lackingevidence-base support.

In an earlier study [16] conducted by the Inventor (Chantal Lau) at thefirst oral feeding of infants born prematurely between 26 and 30 weeksgestation (GA), she defined an infant's OFS as a function of twoparameters: (1) their combined proficiency (PRO(5)), calculated as theratio (%) of volume (ml) taken (ingested, transferred) during the first5 min divided by total volume of liquid prescribed (ml), and (2) theoverall (average) rate of milk transfer (RT₂₀, ml/min), calculated asthe volume of liquid taken over an entire feeding period (ml) divided bythe total length of the feeding period, which generally is 20 minutes(min). The first parameter, PRO(5), being monitored during the first 5minutes of a feeding, was used as an index of infants' true (intrinsic)feeding ability (i.e., when fatigue is minimal). The second parameter,(Rate of Transfer), RT(20), (=overall average flow rate) being monitoredover an entire 20-min feeding duration, was used as an indirect measureof infant's lack of endurance as his OFS skills would weaken withfatigue.

In two studies by Lau [16, 23], it was reasoned that during a feedingsession the average rate of milk transfer (i.e., ml/min) would decreaseover time if infants' true skills were held back due to increasingfatigue. The overall feeding performance or competency (overallpercentage of fluid transferred, OT), is calculated as the ratio (%) ofactual total volume (ml) taken by the infant at the end of a feedingsession, V_(total), divided by the volume of formula initiallyprescribed, V_(prescribed). Feeding was defined as being “successful” ifinfants completed greater than or equal to 80% of their prescribedfeeding volume (i.e., OT 80%). Note that OT is equivalent to PRO(20)measured at the end of a feeding session. Based on their performance,Lau distinguished four levels of Oral Feeding Skills (OFS) for Very LowBirth Weight (VLBW) infants (i.e. those born less than 2.5 Kg), “Level1, 2, 3, and 4” as delineated by two cutoff thresholds: (a) RT₂₀ greateror less than 1.5 ml/min and (b) PRO₅ greater or less than 30% forpremature infants (<34 weeks gestation; and greater or less than 40% forlate preterm and term infants (≥34 weeks gestation). [23, 31]. Thecutoff levels for these two parameters, PRO₅ and RT₂₀, were based on theobservations that VLBW infants demonstrating RT₂₀ 1.5 ml/min and PRO₅30% (or 40%, depending on gestational age) were most likely to besuccessful at feeding, i.e., having an overall transfer (OT) 80% oftheir initial prescribed volume; as well as attaining independent oralfeeding faster than counterparts whose PRO₅ were <30% and/or RT₂₀<1.5ml/min [23]. Compared to this first group, infants with RT₂₀≥1.5 ml/minand PRO<30%, or RT₂₀<1.5 ml/min and PRO 30% also fed successfully(OT≥80%), but attained independent oral feeding at a slower pace.Infants with RT₂₀<1.5 ml/min and PRO₅<30% were not successful at feeding(OT<80%) and were the slowest group to reach independent oral feedingduring their hospitalization thereby prolonging their stay in theneonatal intensive care unit (NICU).

The goal of the study done by the Inventor [23] was to determine whetherthe defined OFS levels can be used as an objective tool for assessingpreterm infants' oral feeding skills; in particular to determine if OFS,as reflected by the combination of proficiency (PRO(5), % ml taken thefirst 5 min/ml prescribed) and rate of milk transfer during a 20-minfeeding session (RT(20), ml/min), correlates with gestational age (GA),oral feeding performance (OT, % ml taken during a feeding/mlprescribed), or days from start to independent oral feeding (SOF-IOF).Lau's working premise was that PRO₅ is reflective of infants' true oractual feeding skills when fatigue is minimal and RT₂₀, monitored overan entire feeding session, is reflective of their overall skills whenfatigue comes into play. Lau hypothesized that: (1) the more mature aninfant's OFS level, the better his/her OT (Overall Transfer, %) at thatfeeding; (2) the more premature an infant (earlier GA), the moreimmature his/her OFS level; and (3) the better the OFS level is, thefaster independent oral feeding will be attained.

Methods [23]:

Infants (26 to 36 weeks GA) with prematurity as their principaldiagnosis were recruited and monitored at their 1^(st) oral feeding. GAwas divided into 3 strata, 26-29, 30-33, and 34-36 weeks GA. OFS wasdivided into 4 levels delineated by PRO₅ or <30% or 40%) and RT₂₀ or<1.5 ml/min). ANOVA with post-hoc Bonferroni and multiple regressionanalyses were used.

Results [23]:

Lau's hypotheses were confirmed. OFS levels were: (a) positivelycorrelated with an infant's feeding performance; i.e., the better theOFS levels, the greater the OT and the shorter the feeding duration; (b)positively correlated with GA strata, i.e., the less premature theinfant, the more mature his/her skills; and (c) inversely associatedwith days from SOF to IOF, i.e., the better the skills, the faster theattainment of independent oral feeding. In summary, OFS levels werecorrelated with GA, OT, PRO₅; and days from SOF-IOF were associated withOFS and GA; whereas RT₂₀ was only with OFS levels. The correlations ofOT and PRO₅ with GA can be explained by the greater proportion ofinfants at the older GA strata, who being more developmentally mature,naturally demonstrated more mature OFS levels. The observation that RT₂₀was associated with OFS, but not GA, suggests that rate of milk transferis primarily regulated by an infant's feeding aptitude, e.g., suckingskills, swallowing skills, suck-swallow-respiration coordination, and/orendurance.

Conclusions [23]:

OFS is a novel objective indicator of infants' feeding ability thattakes into account infants' skills and endurance. Its use does notrequire any special equipment or tool but, rather, the simple monitoringof volume taken at different times during a feeding session. As aclinical tool, it can help caretakers to monitor infants' skills as theytransition to oral feeding, and to identify oral feeding issues arisingfrom immature skills and/or poor endurance. Infants with high PRO₅(≥30%)n and RT₂₀ (≥1.5 ml/min), i.e. OFS level 4 perform better thantheir counterparts with low PRO₅ (<30%, OFS levels 1 and 2) or low RT₂₀(<1.5 ml/min, OFS levels 1 and 3). The observation that infants at OFSlevels 2 and 3 had similar OT suggests that both true feeding skills andendurance are equally important in determining oral feeding success.From this, one may speculate that enhancing both factors would optimizeoverall feeding. This is supported by the observations that OT, PRO₅,RT₂₀, and feeding duration of infants at OFS level 4, were superior tothose of their counterparts at OFS levels 1 to 3.

In summary, we propose that the use of OFS levels is a useful indicatorto assist caregivers in determining infants' oral feeding aptitude. Itis novel and offers an objective assessment of oral feeding skillswhether they are monitored at a 1^(st) oral feeding experience, or on aregular basis as infants mature and advance towards independent oralfeeding (i.e., no tube feeding). Against this background, the presentinvention was developed.

Note: all References listed herein are hereby incorporated by referencein their entirety.

SUMMARY OF THE INVENTION

The present invention comprises a system and methods for assessinginfant oral feeding (OFS) skills during oral feeding. It is also a“Smart” baby feeding system comprising a smart baby bottle wirelesslyconnected to a smart device (e.g., smart phone, tablet, laptop, etc.).“Smart” means that it provides feedback (both immediate andretrospective analytical) to the caregiver: (1) as to when to stopfeeding the baby; (2) as to the quality/efficiency and success of thefeeding; (3) as to the optimum way to feed this particular baby withhis/her unique strengths and weaknesses; and (4) as to the likelihoodthat the baby would benefit from professional attention. It is alsocapable of yielding analytical data for the use of caregivers,professionals, and clinicians within the clinical context if desired.The invention will help optimize the feeding performance, safety, andcompetency of the baby while protecting him/her from harmful feedingpractices that might be detrimental to (impact negatively on) his/herlong-term mental and motor development and/or to mother-infant dyad.

The chain of technologies that make this work starts with a notificationdisplay on the bottle (and/or on a remote device) that is akin to asmartphone screen and/or vibration or auditory sound (e.g., a chimesound) when it receives a signal. This is the immediate feedback methodto the caregiver and is based on the real time OFS level used by theinfant during a feeding (OFS scale levels 1, 2, 3, 4). Signals maycomprise information/message such as: “Feeding is Adequate”, or “StopFeeding”, or “Feeding is Inadequate” (e.g., see “yellow light” in FIG.14). The display screen is controlled by a micro-computer processingdata from one or more sensors located in the feeding bottle or bottlenipple. The logic driving the display notifications comprises innovativealgorithms that are unique to babies.

The data feeding the decision algorithms are derived from one or moresensors located anywhere on the bottle (teat, collar, body, base) and/ornipple. The whole assembly is self-contained and separable from thefeeding bottle body (i.e., an independent instrumentation module) andmay be transferred between bottles; or it may be a permanent feature ofthe bottle. The data collected can be uploaded to a remote processingdevice (a hand-held computer, e.g., smartphone, iPad, iPhone, Android,laptop, etc.) via a proprietary software program or “App” for storageand processing. The App includes algorithms that can analyze the historyof a feeding in order to provide caregivers real time feedback on infantperformance during a feeding, as well as long-term feedback throughretrospective analyses of an infant's feeding history over time, therebyoffering guidance as to differing oral feeding approaches that may beenvisioned. These feeding approaches relate to the variousevidence-based interventions that have been developed, which are basedon where the difficulties lie, e.g., along the oro-gastric pathway (oralcavity, pharynx, lungs, esophageal, etc.). Different algorithms areprovided that are customized for different infants based on their levelof maturity, i.e., very premature, late preterm, term, and also infantswith chronic conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 shows a map of an example of the partitioning of four oralfeeding skill (OFS) levels according to a pair of performanceparameters: (1) proficiency (PRO₅) and (2) rate of milk transfer (RT₂₀)used for very low birth weight infants. Cut-off values of 1.5 ml/min forRT₂₀; and 30% or 40% for PRO₅ are identified for infants born <34 weeksgestation and between 34-36 weeks gestation, respectively [23]

FIG. 2 shows a schematic plot of volume of liquid taken (V(t), ml) andproficiency (PRO, %) versus time (minutes), with four examplesindicating the four different OFS performance levels.

FIG. 3 shows a schematic plot of volume of liquid taken (V(t), (ml) andproficiency (PRO, %) versus time (minutes), for four different examplesthat illustrate the four different OFS levels.

FIG. 4 shows four schematic flow rate profiles of flow rate (ml/min)versus time (minutes) of an infant feeding at four different OFS levels.

FIG. 5 shows a chart of the recommended nutritional constant, K, inKcal/Kg/day using 24, 22, and 20 Kcal/oz, respectively for the threeindividual gestational groups of infants.

FIG. 6 shows a plot of typical prescribed volumes (ml) as a function ofinfant weight (Kg), for three different sets of infants: preterm, latepreterm, and full term; corresponding to caloric contents of 24 Kcal/oz,22 Kcal/oz, and 20 Kcal/oz, respectively.

FIG. 7 plots the proficiency cutoff value, PRO₅, as a function ofgestational age.

FIG. 8 plots the transfer rate cutoff value, RT₂₀ (ml/min), as afunction of gestational age in weeks.

FIG. 9 shows the percent distribution (percent occurrence) of oralfeeding skill (OFS) levels by gestational age GA stratum in infants bornbetween 26 and 36 weeks gestation at their very first oral feedingexperience [23].

FIG. 10 shows Overall Transfer (OT, %) of infants with high vs lowactual feeding skills (PRO₅ greater/less than 30%) vs. endurance (RT₂₀greater/less than 1.5 ml/min) for very low birth weight (VLBW) infantsborn between 26 and 36 weeks gestation at their very first oral feedingexperience [23].

FIG. 11 shows a high-level algorithm for using the smart baby bottlewith a smart device and embedded application.

FIG. 12 shows an example of a first algorithm for determining OFSlevels.

FIG. 13 shows a flow chart of a second example of an algorithm forsorting feeding performance into the four OFS levels 1, 2, 3, 4.

FIG. 14 shows Table 5 with 9 different scenarios, based on the flowchart of FIG. 13.

FIG. 15 shows an example of a third algorithm for determining OFSlevels.

FIG. 16 shows a schematic perspective view of a smart infant feedingbottle system communicating wirelessly with a smart phone (e.g., smarttablet, or personal computer).

FIG. 17A shows a cross-section, exploded view of an embodiment of a flowrate module for an OMK system, according to the present invention.

FIG. 17B shows a cross-section view of an assembly of FIG. 17A.

FIG. 18A shows a cross-section, exploded view of another embodiment of aflow rate module for an OMK system.

FIG. 18B shows a cross-section view of an assembly of FIG. 18A.

FIG. 19A shows a cross-section, exploded view of another embodiment of aflow rate module for an OMK system.

FIG. 19B shows a cross-section view of an assembly of FIG. 19A.

FIG. 20 shows a schematic micro flow rate sensor printed circuit boardassembly for use inside of an infant feeding bottle (cover removed forclarity).

FIGS. 21-A,B,C show a cross-sectional view (FIG. 21A) and two overallviews (FIG. 21B,C) of a self-paced ergonomic feeding bottle, accordingto the patent application mentioned above. The present invention can usethis type of feeding bottle.

FIG. 22 shows a performance map for the OFS scale based on OT (%) froman earlier study [23]

FIG. 23 shows a plot of infant birth weight (Kg) versus Gestational Ages(weeks) for female infants, including percentile ranges.

FIG. 24 shows a chart detailing the components of an Advanced FeedingDevice, according to the present invention.

FIG. 25 shows a side cross-section view of an example of a flow ratesensor disposed inside of an instrumentation module that is mounted tothe outside of the bottle, on the bottle's side.

FIG. 26 shows an exploded side cross-section view of an example of aflow rate sensor disposed inside of an instrumentation module that ismounted to the outside of the bottle, on the bottle's side.

FIG. 27 shows a side cross-section view of an example of a flow ratesensor disposed inside of an instrumentation module that is mounted tothe outside of the bottle, on the bottle's side.

FIG. 28 shows an elevation view of another example of a flow rate sensordisposed inside of an instrumentation module that is mounted to theoutside of a feeding bottle, on the bottle's side.

FIG. 29 shows an isometric view of another example of a flow rate sensordisposed inside of an instrumentation module that is mounted to theoutside of a feeding bottle, on the bottle's side.

FIG. 30 shows an isometric view of another example of a flow rate sensordisposed inside of an instrumentation module that is mounted to theoutside of a feeding bottle, on the bottle's side.

FIG. 31 shows a photograph of a disassembled prototype air flow ratesensing module and associated tubing.

FIG. 32 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing.

FIG. 33 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing connected to the upperinlet of a water bottle.

FIG. 34 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing connected to the upperinlet of a water bottle, with a siphon attached to the water bottle fordraining water out of the upper bottle down into a lower bottle.

FIG. 35 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing connected to the upperinlet of a water bottle, with a siphon attached to the water bottle fordraining water out of the upper bottle down into a lower bottle, withthe lower bottle placed at a different height.

FIG. 36 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing connected to the upperinlet of a water bottle, with a siphon attached to the water bottle fordraining water out of the upper bottle down into a lower bottle, withthe lower bottle placed at a different height.

FIG. 37 shows a photograph of an assembled prototype air flow ratesensing module and associated air flow tubing connected to the upperinlet of a water bottle, with a siphon attached to the water bottle fordraining water out of the upper bottle down into a lower bottle, withthe lower bottle placed at a different height.

FIG. 38 shows a plot of measured differential pressure (Pa) across theairflow sensor versus time (s) for a static siphon.

FIG. 39 shows a plot of measured total volume (mL) versus time (s) for astatic siphon.

FIG. 40 shows a plot of measured total volume (mL) versus time (msec)for a transient siphon with step changes in height, illustrating therange of dynamic response.

FIG. 41 shows a plot of measured incremental volume (mL) versus time(msec) for a transient siphon with step changes in height, illustratingthe range of dynamic response.

FIG. 42 shows a plot of measured pressure (Pa) versus time (msec) for atransient siphon with step changes in height, illustrating the range ofdynamic response.

FIG. 43 shows a 3-D map of an example of the partitioning of four oralfeeding skill (OFS) levels 1-4 according to a pair of performanceparameters: (1) endurance and (2) feeding skills

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-43 show examples of various embodiments of the presentinvention. Note: the term “smart device” or “remote device” refers toany type of wireless or wired smart phone (e.g., iPhone®), smart tablet(e,g. iPad®), laptop, personal computer (PC), or desktop data processingdevice, such as a Biopac® data collection unit, using a wirelessprotocol such as Bluetooth®.

Note: Infants may be categorized by their gestational age (GA) or birthweight. Preterm infants are born ≤36 weeks gestational age (GA) anddifferentiate between extremely preterm (<28 weeks), very preterm (28 to<32 weeks), moderate preterm (32-33 weeks), late preterm (34 to 36weeks). Full-term infants range between 37 to 42 weeks gestation. Byweight, extremely low birth weight infants are born <1000 g, very lowbirth weight between 1000 g to <1500 g, low birth weight between 1500 gand <2500 g, full term between 2500 and 4200 g.

Infant birth weight (Kg) generally increases with gestational age(weeks), as shown in FIG. 23.

FIG. 1 shows a map of an example of the partitioning of oral feedingskill (OFS) into 4 distinct levels: 1, 2, 3, 4 according to a pair ofperformance parameters: (1) proficiency (PRO₅) and (2) rate of milktransfer (RT₂₀). The PRO₅ cutoff is defined as the % volume (ml) takenduring the first 5 min, i.e., V(5), divided by the total volume (ml) ofliquid prescribed, V_(prescribed). RT₂₀ is defined as the overall rateof milk transfer (ml/min) averaged over an entire 20-minute feedingsession. In this example, which applies to premature infants [Lau, 23],the cutoff (i.e., threshold), PRO₅, between ‘poor’ and ‘good’ skills isset at PRO₅=30% or 40%, depending on whether infants are ≤33 weeks or≥34 weeks gestation, respectively; and the cutoff, RT₂₀, between ‘poor’and ‘good’ endurance is set at RT₂₀=1.5 ml/min for gestational ages of25-36 weeks; RT₂₀=3.0 ml/min for gestational ages of 37-42 weeks.

The proficiency parameter (PRO₅), which is measured within the first 5minutes of feeding, is taken as an indirect marker for a baby's inherentoral feeding skills when fatigue is minimal (˜0). On the other hand, theoverall rate of transfer (RT₂₀, ml/min), which is averaged over anentire feeding session, is taken as an indirect marker for an infant'saverage oral feeding skills when fatigue comes into play. Note: thefeeding duration is typically limited to a maximum of no more than 20minutes for premature infants. For strong feeders (near-term and termbabies), however, the feeding time can be as short as 5-10 minutes.Note: The OFS scale can be divided into any different number of levels,e.g., 1, 2, 3, 4, 5, or 6 levels, with appropriate cutoff (threshold)values defining and differentiating the different levels of infants'prematurity.

FIG. 2 shows a schematic plot of volume of liquid taken (V(t); ml)versus time (minutes), with four examples indicating the four differentOFS performance levels: 1, 2, 3, 4. Infants with poor endurancegenerally transfer (ingest), on average, less than 25% of theirprescribed volume, while infants with good endurance generally transfergreater than 60% of the prescribed volume, at the end of a feedingsession. Infants with good skills and good endurance generally transfergreater than 90% of the prescribed volume in a session.

FIG. 3 shows a schematic plot of volume of liquid taken (V(t); ml)versus time (minutes), also known as “Proficiency” (PRO) in % whennormalized to the volume prescribed, V_(prescribed), for four differentexamples that illustrate the four different OFS levels. The proficiency,in general, can be measured (1) at discrete intervals (e.g., every 5minutes, or every 1-2 minutes) by weighing the bottle and subtractingthe weight from an initial weight and then converting the weight changeto a volume change by the liquid's density; or (2) continuously by usingan in-situ volume-measuring or weight-measuring sensor disposed insideof, or outside of, the feeding bottle that continuously measures thevolume or weight remaining (and subtracting from the initial volume orweight).

Alternatively, the instantaneous volume taken, V(t), can be calculatedfrom measurements of the flow rate (ml/min) by taking the integral of aninstantaneous flow rate, FR(t), times a time increment (dt), over a timeperiod from t=t₁ to t=t₂, according to eq. (1), as follows:

V(t)=INTEGRAL_([t=t1 to t2]){FR(t)·dt}(ml)  (1A)

The time period t₁ to t₂ can be as short as a single suck (e.g., 1second), in which case the integrated volume equals the bolus volumetaken for a single suck, or it can be as long as 20 minutes, in whichcase the integrated volume equal the total volume taken during a feedingsession. The instantaneous flow rate, FR(t), is equal to the timederivative of the volume taken, V(t), as follows:

FR(t)=dV(t)/dt(ml/min)  (1B)

Note, when the experimental data fall below the bottom line in FIG. 3,the OFS level is equal to 1 and the caregiver should stop feedingbecause of the low rate of milk transfer (OT less than 25% after themaximum allowed period of 20 minutes). Infants with poor skillstypically transfer less than 30% of the volume prescribed after 5minutes, while infants with good skills typically transfer more than 50%of the volume prescribed after 5 minutes. Infants with good skills andgood endurance (OFS level 4) can complete a typical feeding in less than20 minutes (e.g., around 10 minutes, with an Overall Transfer, OT=100%).At the opposite extreme, infants with poor skills and poor endurance(OFS level 1) typically ingest less than 50% of the total volumeprescribed over the maximum allowed 20 minutes (e.g., Overall Transfer,OT=20-30%).

FIG. 4 shows a schematic plot of examples of flow rate (ml/min) versustime (minutes) of four different sample flow rate curves. The flow ratesnaturally declines over time as the infant fatigues and feeding slowsdown. An average flow rate can be determined in a couple of differentways. It can be calculated by taking the time derivative of theinstantaneous curve of volume taken versus time (i.e., FIG. 3). Thisgives the average flow rate averaged over the period of timecorresponding to the period of a single suck. The time derivative can becalculated at discrete intervals (e.g., every 5 minutes, or every 1-2minutes), or it can be calculated at an essentially continuous rate byusing a very small delta-time interval (e.g., 0.1 seconds). The timederivative can be calculated using a variety of approximate formulas,depending on the particular time interval chosen, as is well known inthe art, and as is readily available in mathematical functions andstatistical programs. The instantaneous flow rate (ml/sec) can also bemeasured directly in a continuous manner by an in-situ flow rate sensordisposed inside of the feeding bottle (see below). Alternatively, thebottle can be weighed at periodic intervals (e.g., every 5 minutes), anddifferences taken to get the volume ingested via the liquid's density.

The optimum amount of liquid prescribed to be taken in a single feedingsession, V_(prescribed), can optimally be calculated according to aninfant's weight, W (kg) using the following nutritional rate constant,K, for premature infants where:

K=120(Kcal/kg/day)  (2)

This nutritional rate constant, K, has been selected so that the infantattains an optimum rate of weight gain of about 15 g/Kg/day. Optionally,the nutritional rate constant, K, can range from 100 to 120 Kcal/Kg/day,depending on the infant's gestational age (See FIG. 5). Accordingly, thevolume prescribed, V_(prescribed), is given by eq. (3), in terms ofKcal/day.

V _(prescribed)(per day)=K×W(Kcal/day)  (3)

Then, assuming a nutritional density of the infant formula as being=0.8Kcal/ml (which equals 24 Kcal/30 ml or 0.8 Kcal/ml), then eq. (3) can beconverted to a daily volumetric intake according to eq. (4):

V _(prescribed)(per day)=K×W/0.8(ml/day)  (4)

Finally, depending on the number of feeding sessions per day, N, theamount of liquid prescribed to be taken in a single feeding session canbe calculated by:

V _(prescribed)(per session)=1.25×K×W/N(ml/session)  (4A)

For example, assuming an infant's weight is 1 Kg (a very low birthweight infant), and N=8 sessions/day, and K=120 Kcal/kg/day, then eq.(5) gives a prescribed volume of:

V _(prescribed)=150×⅛(ml/session)  (5)

V _(prescribed)=18.75(ml/session)  (6)

Preferably, the nutritional constant, K, is decreased with increasedgestational age. Typically, feeding formulas with a high nutritionalcalorie content (calorie density) of 24 Kcal/oz are used for very lowbirth weight premature infants. Then, as the infant matures and gainsweight appropriately, lower caloric content formula can be used; i.e.,transitioning to 22 kcal/oz, and then to 20 kcal/oz formulas when thebaby is discharged from the hospital. Note: one can reduce totalcalories by either using a less caloric-rich formula, or by decreasingthe total volume of the original formula offered. However, properhydration is essential; so the need for hydration must be evaluated atthe same time. These changes are factored into FIG. 5, which shows achart of the nutritional constant, K, in Kcal/Kg/day versus gestationalage in weeks.

For late pre-term infants, K=110 Kcal/Kg/day, and equation 4A ismodified as follows:

V _(prescribed)=137.5×W/N(ml/session)  (4B)

For full-term infants, K=100 Kcal/Kg/day, and equation 4A is modified asfollows:

V _(prescribed)=125×W/N(ml/session)  (4C)

FIG. 6 shows a plot of typical prescribed volumes (ml) per day as afunction of infant weight (Kg), for three different sets of infants:Preterm, Late Preterm, and Full Term; corresponding to nutritionalcaloric contents equal to 24 Kcal/oz, 22 Kcal/oz, and 20 Kcal/oz,respectively. The daily volume prescribed, V_(prescribed), increaseslinearly with weight (within a selected age group). In clinicalpractice, regardless of how premature the infants were at birth, whenthey gain around 3 Kg, and close to discharge, they are transitioned toa 22 Kcal/oz formula, and then to a 20 Kcal/oz formula, especially atthe time when they are discharged home. One wants to get back to a 20Kcal/oz formula when infants are home and feeding ad libitum, i.e., nomore than prescribed volume (infants generally eat until they have hadenough). Table 1A shows the prescribed volume, V_(prescribed), as afunction of Formula Strength (Kcal/oz) and nutritional constant, K(Kcal/kg/day).

TABLE 1A Prescribed Volume, V_(prescribed), per Kg per day FormulaStrength Nutritional 20 Kcal/oz 22 Kcal/oz 24 Kcal/oz Constant, K (30ml) (30 ml) (30 ml) 120 Kcal/kg/day 180 ml/kg/day 164 ml/kg/day 150ml/kg/day 110 Kcal/kg/day 165 ml/kg/day 150 ml/kg/day 137 ml/kg/day 100Kcal/kg/day 150 ml/kg/day 136 ml/kg/day 125 ml/kg/day

Depending on the gestational age of the premature infant, the OFS cutofflevel for proficiency (PRO₅) may vary from 25% for very low birth weightinfants to 40% for near pre-term infants. In contrast, the OFS cutofflevel for rate of transfer, RT₂₀, stays relatively constant at 1.5ml/min for premature infants, independent of the infant's gestationalage. For full-term babies, the OFS cutoff level for proficiency (PRO₅)may be as high as 50%; and the cutoff for overall flow rate averagedover a feeding session, RT₂₀, may be significantly higher, e.g., in therange of 5-10 ml/min.

FIG. 7 plots the proficiency cutoff value, PRO₅, as a function ofgestational age. Here, the proficiency cutoff, PRO₅, increases withincreasing gestational age insofar as in-utero maturation increases thelonger the gestational period, with PRO₅ doubling in value from 25% to50% for a GA of 25 weeks to 40 weeks. In particular, PRO₅=30% for GA inthe range of 25-33 weeks; PRO₅=40% for GA in the range of 34-36 weeks;PRO₅=50% for GA in the range of 33-42 weeks.

FIG. 8 plots the transfer rate cutoff value, RT₂₀ (ml/min) as a functionof gestational age in weeks. The RT₂₀ cutoff value increases withincreasing gestational age. In particular, RT₂₀=1.5 for GA in the rangeof 25-33 weeks; RT₂₀=1.5 for GA in the range of 34-36 weeks; RT₂₀=3.0for GA in the range of 33-42 weeks.

FIG. 9 shows an example of the percent distribution (percent occurrence)of oral feeding skill levels by gestational age stratum in infants bornbetween 26 and 36 weeks gestation, at their very first oral feedingexperience [23]. It can be seen that the more premature the infants(26-29 weeks gestation at birth), the greater the percentile of infantswith the most immature oral feeding skills, i.e., OFS level 1.Conversely, the less premature the infants are (34-39 weeks gestation atbirth), the greater the percentile of infants with the most mature oralfeeding skills, i.e., OFS level 4.

FIG. 10 shows the Overall Transfer (OT, %) of the same group of infantsmonitored at their very first oral feeding experience, as a function ofthe respective maturation levels of their oral feeding skills; namelyinfants with high vs low actual feeding skills (PRO greater/less than30%) vs. endurance (RT₂₀ greater/less than 1.5 ml/min) for very lowbirth weight (VLBW) infants born between 26 and 36 weeks gestation [23].Overall Transfer (OT, %) is defined as the ratio of total fluid taken atthe end of a feeding session divided by the total volume of liquidprescribed, usually expressed as a percentage. As expected, a low OFSlevel 1 (poor skills, poor endurance) corresponds to a low OverallTransfer (OT) ratio, averaging around 30%±24% (SD). And, as expected, ahigh OFS level 4 (good skills, good endurance) corresponds to a highoverall transfer ratio, averaging around 96%±12% (SD). What is somewhatsurprising is that the intermediate OFS levels 2 and 3 also correspondto a high overall transfer rate, with OFS level 2 averaging 85%±17% andOFS 3 averaging 78%±21%. This indicates that either good skills or goodendurance (or both) are important for achieving successful feedingperformance (defined as OT≥80%). In summary, according to FIG. 10, theOT value is useful for distinguishing between OFS level 1 and OFS levels2, 3, and 4, but not particularly useful for distinguishing between OFSlevels 2, 3, and 4.

FIG. 11 shows a first example of a high-level methodology for using thesmart baby bottle with a smart device and embedded application (“APP”).In step 100, the feeding protocol is defined by the caregiver and smartdevice application, based on the infant's weight (Step 60) andgestational age (Step 50), for a range of nutritional requirements. Instep 70, the volume prescribed (V_(prescribed)) is calculated, based onthe needed nutritional constant, K, and infant's weight, W. Next, instep 200, the instantaneous feeding performance (e.g., Proficiency,PRO(t), and flow rate, FR(t), is measured over time while feeding by theOMK instrumentation module in the smart (instrumented) bottle.Optionally, the overall rate of transfer, OT, can be measured in step200. Next, in step 300, the OFS skill levels (1, 2, 3, 4) are determinedby using the algorithm(s) built into the smart device's application(APP) (see, e.g., Tables 2, 3, or 4). Then, in step 400, if OFS<3, thenmaintain the feeding protocol for about 2 days. Next, in step 500, ifOFS remains <3, then implement Feeding Interventions for another 2 days.Next, in step 600, if OFS remains <3, then change interventions foranother 2 days. Next, in step 700, if there is no change, then consultPediatric Subspecialties (e.g., Gastroenterology (GI), Ear-Nose-Throat(ENT), etc.). If OFS=4 at any point in time, then the performance is“successful”. After feeding is completed, the final level of OFS (1, 2,3, or 4) is displayed or announced by the smart device, and theapplication suggests a variety of possible interventions(recommendations) for improving feeding performance if OFS=1, 2, or 3.If OFS=1 (poor skills, poor endurance) at any point in the feeding, thenthe smart device alerts the caregiver to STOP feeding the infant bydisplaying or announcing “Stop Feeding” (step 500). If OFS=4, thefeeding performance is displayed as “successful”, and no interventionsare suggested. The performance data are saved by the smart device forfuture retrospective analyses and longitudinal study.

FIG. 12 shows a second example of an algorithm for determining OFSlevels. FIG. 12 follows the simplified algorithm defined in Table 1.Note: the parameter PRO(5) is defined as the % volume (ml) taken duringthe first 5 min divided by the total volume (ml) of liquid prescribed.The parameter RT(20) is defined as the overall (average) rate of milktransfer (ml/min) averaged over an entire 20 minute feeding session. Thealgorithm starts with inputting the gestational age (GA), weight (W), ofthe infant, and the number of feeding sessions in a day, N. Then, usingthe gestational age, the cutoff values of PRO₅, and RT₂₀, and K(nutritional constant) are determined by looking up the appropriatevalues in Table 1 or by evaluating a programmed equation. Then, theprescribed volume of fluid to be taken, V_(prescribed), is calculatedusing the appropriate eq. (4A or 4B or 4C). Then, feeding begins in step1000. Next, in step 1050 the volume taken (ingested), V(t), is measuredafter time=5 and 20 minutes either by direct measurement, or by weighingthe bottle and calculating the change in weight, then converting theweight change to volume of liquid taken, V(t) via the density (as milkdensity is equal to 1.011 g/cc). At time=5 minutes, the proficiencyparameter, PRO (%) is calculated, using the measured volume of fluidtaken after 5 minutes, V(t=5 min), according to eq. (7A):

PRO(5)=V(t=5 min)/V _(prescribed)×100(%)  (7A)

Then, in step 1100 the average flow rate, RT(20), (ml/min) at 20 minutesis calculated or measured according to eq. (7B):

RT(20)=V(t=20)/20(ml/min)  (7A)

Next, in step 1200, the measured PRO(5) value is compared to the PRO₅cutoff (i.e., PRO₅=30% for VLBW infants or 40% for late preterm and terminfants, respectively). Then, in step 1300 and 1600, the measured FlowRate, RT(20), is compared to the cutoff value of RT₂₀=1.5 ml/min.Depending on the results of the comparisons in steps 1400, 1500, 1700and 1800, the intermediate OFS level is determined according to Table 2,3, or 4 below (depending on the gestational age), and displayed on adisplay unit (e.g., smartphone, tablet, or computer monitor), along withthe elapsed time since start of feeding. If the OFS level is equal to 1,then the baby is having significant difficulty feeding and feedingshould STOP and be assessed. Note that the Overall Transfer (OT, %),given by eq. (8), is equal to the final value of the calculatedproficiency parameter PRO (i.e., at time=20 minutes):

OT=PRO(t=20)=V(t=20)/V _(prescribed)×100(%)  (8)

The average rate of transfer, RT(20), is typically less than the initialrate of transfer, RT(0), because of the development of fatigue duringfeeding.

Once RT(20) is calculated, this can be compared with the cutoff value,RT₂₀, for making a final determination of the overall OFS level,depending on the Gestational Age of the infant.

TABLE 1 OFS Algorithm #1 for very low birth weight infants OverallPerformance: If PRO(5) ≥ 30% → OFS level = 3 or 4; If RT(20) ≥ 1.5ml/min → OFS 4; If RT(20) < 1.5 ml/min → OFS 3; If PRO(5) < 30% → OFSlevel = 1 or 2; If RT(20) ≥ 1.5 ml/min → OFS 2; If RT(20) < 1.5 ml/min →OFS 1 → STOP feeding.

Depending on the results of the comparisons, the OFS level is finallydetermined according to the logic listed in Table 2, 3, or 4, anddisplayed on a display unit (e.g., smartphone, tablet, or computermonitor). Note: PRO(5)=proficiency at t=5 min, and RT(20)=average rateof transfer after t=20 min. For infants that are pre-term, then Table 2should be used.

TABLE 2 Determination of OFS Level for GA = 25-33 weeks If PRO(5) ≥ 30%and RT(20) ≥ 1.5 ml/min, then OFS = 4; If PRO(5) ≥ 30% and RT(20) < 1.5ml/min, then OFS = 3; If PRO(5) < 30% and RT(20) ≥ 1.5 ml/min, then OFS= 2; If PRO(5) < 30% and RT(20) < 1.5 ml/min, then OFS = 1.

For infants that are late pre-term, Table 3 should be used.

TABLE 3 Determination of OFS Level for GA = 34-36 weeks If PRO(5) ≥ 40%and RT(20) ≥ 1.5 ml/min, then OFS = 4; If PRO(5) ≥ 40% and RT(20) < 1.5ml/min, then OFS = 3; If PRO(5) < 40% and RT(20) ≥ 1.5 ml/min, then OFS= 2; If PRO(5) < 40% and RT(20) < 1.5 ml/min, then OFS = 1.

For infants that are term, Table 4 should be used.

TABLE 4 Determination of OFS Level for GA = 37-42 weeks If PRO(5) ≥ 50%and RT(20) ≥ 3 ml/min, then OFS = 4; If PRO(5) ≥ 50% and RT(20) < 3ml/min, then OFS = 3; If PRO(5) < 50% and RT(20) ≥ 3 ml/min, then OFS =2; If PRO(5) < 50% and RT(20) < 3 ml/min, then OFS = 1.

FIG. 13 shows a flow chart of a third example of an algorithm forsorting feeding performance into the four OFS levels 1, 2, 3, 4. Thisalgorithm is based on measuring the flow rate at 5 minute intervals(e.g., based on weighing the bottle every 5 minutes). The cutoff rangesof Flow Rate, FR, (e.g., 0-4, and 5-9, and ≥10 ml/min), are appropriatefor pre-term and late pre-term infants. OFS levels 2 and 3 are groupedtogether into the “Yellow” group, since their overall volumetrictransfer (OT, %) are roughly the same in both groups (80-90%).

FIG. 14 shows Table 5 with 9 different scenarios (possible histories),based on the flow chart of FIG. 13. The following parameters are definedin Table 6:

TABLE 6 Parameter Definitions FR(5) = FR(0-5) = average flow rate from0-5 minutes; FR(10) = FR(6-10) = average flow rate from 6-10 minutes;FR(15) = FR(11-15) = average flow rate from 11-15 minutes; FR(20) =FR(16-20) = average flow rate from 16-20 minutes.

Referring still to FIG. 14, the following visual scale is defined asbeing associated with a particular flow rate and OFS level (Table 7):

TABLE 7 Visual Symbol Associations Green = G = “good” = flow rate ≥ 10ml/min = OFS level 4; Yellow = Y = “be watchful” = flow rate = 5-9ml/min = OFS level 2 or 3; Red = R = “stop” = flow rate = 0-4 ml/min =OFS level 1; Stop = S.

The OT range, Comments, and Recommendations listed in FIG. 14 are basedon our studies [23,31].

At each measurement point in time (e.g., 5, 10, 15, or 20 minutes), thevolume of fluid taken (ingested) is measured (e.g., by weighing thebottle, or by using an instrumented flow monitoring system), and acalculation of the average flow rate during the preceding 5 minutes isperformed. This value is sorted into one of three possible bins: (≥10ml/min, 5-9 ml/min, or 0-4 ml/min), and a color is assigned (green,yellow, red), which can be displayed to the caregiver on a display uniton the bottle or on a remote device. At the same time, an optionalaudible alert can be given by the display unit, using the followingscale (Table 8):

TABLE 8 Audio Associations (soft sounds) Green = good = OFS 4 = one“bip”; Yellow = be watchful = OFS 2 or 3 = two bips: “bip-bip”; Red =stop = OFS 1 = three bips: “bip-bip-bip”.

Alternatively, a visual scale can be displayed on a display unit thatshows vertical bars (similar to multiple bars for signal strength of awireless phone or wireless network), according to the following scale(Table 9):

TABLE 9 Visual Bar Associations Green = good = OFS 4 = three verticalbars; Yellow = be watchful = OFS 2 or 3 = two vertical bars; Red = stop= OFS 1 = one vertical bars.

Alternatively, an opposite type of visual scale can be displayed, whichcorrelates the number of vertical bars to the OFS scale, according toTable 10:

TABLE 10 Alternative Option for Visual Bar Display Associations OFSlevel 4 = 4 vertical bars; OFS level 3 = 3 vertical bars; OFS level 2 =2 vertical bars; OFS level 1 = 1 vertical bar.

Alternatively, a computer synthesized set of audio instructions(statements) can be “spoken” by the monitor, smartphone, tablet, orcomputer, according to Table 11:

TABLE 11 Audio Statements (soft sounds) Green = good = OFS 4 = “Baby isfeeding well”; Yellow = be watchful = OFS 2 or 3 = “Baby is started totire”; Red = stop = OFS 1 = “Baby needs to stop feeding”.Optionally, the user can turn off the audio announcements and/or audiostatements, in order to have a quiet environment.

FIG. 15 shows an example of a fourth algorithm for determining OFSlevels. FIG. 15 follows the simplified algorithm in Table 12.

TABLE 12 OFS Algorithm #3 Overall Performance: If PRO(t) ≥ 6 · t (%) →OFS level = 3 or 4; If RT(20) ≥ 1.5 ml/min → OFS 4; If RT(20) < 1.5ml/min → OFS 3; If PRO(t) < 6 · t (%) → OFS level = 1 or 2; If RT(20) ≥1.5 ml/min → OFS 2; If RT(20) < 1.5 ml/min → OFS 1 → stop feeding; andIf PRO(t) < 2 · t (%) → OFS 1 → stop feeding;

In this scheme, Table 12, the first cutoff for OFS determination isbased on a constant rate of volumetric transfer equal to 6% per minute(which equates to 30% after 5 minutes of feeding). Using theinstantaneous volumetric rate of fluid transfer (i.e., %/min) allows fora more generalized assessment to be performed at any time, t, (e.g.,every 1 minute), rather than doing it only at a fixed time (e.g., at t=5minutes). This would be useful in conjunction with an instrumented smartbottle, for example. Assuming the infant transfers fluid at a constantrate of about 6%/minute initially without any fatigue, this means thatthey can transfer 100% of the prescribed volume in about 17 minutes.Strong feeders transfer fluid at a much faster volumetric rate, e.g. at12%/min; which means that they can transfer 100% of the prescribedvolume in about 8 minutes without fatigue.

In this scheme shown in FIG. 15, the parameter V(t) is the volume taken(ingested) by the infant as a function of time, t. The parameter PRO(t)is defined as the volumetric proficiency (as a function of time, t),which is equal to the ratio of volume taken (from beginning to time=t)divided by the prescribed volume (from Eq. 4A, 4B, or 4C), as follows:

PRO(t)=V _(taken)(t)/V _(prescribed)×100(%)  (9)

Here, we note that at t=5 minutes, the proficiency is equal to PRO(5):

PRO(t=5)=PRO(5)  (10)

In a similar fashion, the average rate of transfer, RT(t) can be definedas the secant average feeding rate (flow rate) averaged over the periodof time, t, (i.e., from 0 to t minutes), and is given by equation (12)as follows:

RT(t)=V(t)/t=PRO(t)×V _(prescribed) /t(ml/min)  (11)

Note that by using eq. 9, eq. (11) can be rewritten as:

RT(t)=PRO(t)×V _(prescribed) /t(ml/min)  (12)

Note that the value at t=20 minutes, RT(20), is equal to the averageoverall transfer rate value, as follows:

RT(t=20)=PRO(20)×V _(prescribed)/20  (13)

In summary, the use of OFS levels can offer a more objective, real timeindicator of infants' ability to feed by mouth than Gestational Age (GA)or other tools currently available. It does not claim to provide theultimate answer for solving infants' oral feeding difficulties, as thelatter are multi-factorial. However, it does offer the ability todifferentiate between feeding aptitude and endurance/fatigue, which areboth equally important for oral feeding success.

The use of an OFS scale coupled with an assessment algorithm offersseveral features. (1) It is easy to measure, as caregivers need onlycollect the volume reading at, for example, 5 minutes into the feedingsession (in addition to the routine information routinely collected,i.e., volume prescribed, volume taken, and feeding duration). (2) Nospecial equipment is required. (3) It provides an objective rather thansubjective assessment of infants' feeding skills during a feedingsession. (4) As infants of similar GA differ in OFS, evaluating theirlevels prior to the introduction of oral feeding can help identifyinfants' ability when oral feeding is initiated. (5) Measuring OFSlevels does not only pertain to infants' first oral feeding. MonitoringOFS longitudinally (i.e., over a period of weeks) as infants wean fromtube feeding provides information on their maturation process. (6) Itcan be used as an indicator of whether oral feeding should be advancedor held back. (7) Additionally, if an infant is receiving a particularintervention, monitoring over time can help determine the intervention'sefficacy.

OFS levels may also assist caregivers to identify whether infants' oralfeeding issues relate to skill levels or to endurance (or both). Forinstance, if an infant exhibits an OFS level of 1, with low skill andendurance, he/she may benefit from both oral feeding therapy and‘endurance training’ (see below, and FIG. 14). An OFS level 2 infantwith low skill and high endurance would likely only require oral feedingtherapy; whereas an OFS level 3 infant with high skill and low endurancewould benefit primarily from ‘endurance training’. An infant at OFSlevel 4 would need no intervention.

An important purpose, therefore, of monitoring an infant's feedingperformance and then sorting the infant's performance into one of fouroral feeding skill (OFS) levels, is to provide useful feedbackinformation to the caregiver to allow him/her to implement pertinentinterventions aimed at improving the feeding performance. Overall, if aninfant's Overall Transfer rate (OT, ml/min) is ≥80%, then the feeding isgenerally considered “successful” and 1-2 days are allowed formaturation to occur. However, if OT<80%, intervention should beconsidered. Table 10 lists potential interventions that can beconsidered, based on the specific OFS level:

TABLE 10 Suggested Interventions to Consider OFS Feeding skillsEndurance Levels (PRO) (RT) Potential interventions 1 Poor PoorAppropriate evidence-based directed intervention(s) + “oral endurancefeeding training” 2 Poor Good Appropriate evidence-based directedintervention(s) 3 Good Poor “oral endurance feeding training” 4 GoodGood none

In order to prevent negative oral feeding experiences and/or excessivefatigue [22], an endurance training program may be implemented. This mayconsist of daily, shortened feeding sessions, the total duration ofwhich equals the duration corresponding to the number of oral feedingsper day ordered (prescribed). For instance, if an infant is allowed tofeed once a day for a maximum of 20 min, but at the first feeding onthat day, he/she exhibits signs of fatigue, disorganization, and/orunstable behavioral state after 5 min, the ‘endurance training’ mayconsist of four, 5-min feedings on that particular day (for the sametotal of 20 min.). Feeding duration can be gradually increased on adaily basis as the above symptoms decrease. This type of training isbased on the general acceptance that ‘practice makes perfect’, in theabsence of adverse events or chronic conditions.

For OFS level 2, another example of an evidence-based feedingintervention can comprise performing non-nutritive oral motor therapy(NNOMT). The NNOMT protocol [Fucile, 19] comprises stroking the cheeks,lips, gums and tongue for 12 minutes, concluding with a 3-minute activesucking on a pacifier. Other time intervals can be used, as well. Seealso references [20] and [21].

Another example of an evidence-based feeding intervention canadditionally (or optionally) comprise using a self-paced feeding bottle[24]. This type of bottle design has a vent hole for preventing theundesirable buildup of internal vacuum as the fluid empties from thebottle. Also, the self-paced bottle has a unique liquid-feeding setupthat prevents the development of positive hydrostatic pressure, whichbuilds up when the bottle is tilted at too great an angle to thehorizontal, leading to a continual dripping of milk into the infant'smouth. If the infant is not ready to feed, such dripping may lead toadverse events such as choking, fluid aspiration into the lungs. It wasshown in [24] that very low birth weight infants significantly improvedtheir OFS levels, from mostly OFS 1 to mostly OFS 4, when a self-pacedfeeding bottle was substituted for a standard (non-vented) feedingbottle. FIGS. 21A, 21B, and 21C shows different views of an example of aself-paced, ergonomic feeding bottle, according to the presentinvention.

Another example of an evidence-based feeding intervention can compriseperforming non-nutritive sucking exercises using pacifiers. This can beachieved by gently moving the pacifier in a rhythmic up/downposterior/anterior motion that stimulates the infants' non-nutritivesucking. However, research has shown that this particular interventionis not especially effective.

Another example of an evidence-based feeding intervention can compriseperforming swallowing exercises. This can comprise placing a bolus of0.05-0.2 mL of the type of milk the infant was receiving at the time(that is, mother's milk or formula) via a 1-mL syringe directly on themedial-posterior part of the tongue approximately at the level of thehard and soft palate junction (close to the site where the bolus restsprior to entering the pharynx). The infants are started with 0.05 mL,and the volume increased in increments of 0.05 mL to a maximum of 0.2mL, until the swallowing reflex was observed or as tolerated, (i.e., theintervention was halted at any sign of adverse events, e.g., unstablevitals, choking, fatigue, or disorganization). Once the minimal volumenecessary to initiate the swallow reflex is visually identified, it isused for the remaining duration of the exercise. The exercise can beprovided every 30 seconds over a 15-minute programme, or as tolerated.In general, it was found that the use of these specific swallowingexercises caused more rapid maturation of oral feeding skills than theuse of sucking exercises using pacifiers, as evidenced by theimprovement in OFS levels from 1 to 4 among the population studied [25].

Another example of an evidence-based feeding intervention can compriseperforming infant massage therapy (iMT). This intervention can comprisestroking the head, neck, back, arms and legs for 10 minutes, combinedwith passive range of motion applied to the limbs for 5 minutes [27].Optionally, both NNOMT and iMT therapies can be combined. The studiesfound that infants who received the NNOMT and/or iMT interventionsdemonstrated a faster rate of OFS maturation than their controlcounterparts, and with fewer occurrences of the lowest OFS level, level1 [26, 28]. Another example of an evidence-based feeding interventioncan include changing feeding positions from among supine, sidelying,prone, and upright.

Differences between the effectiveness of the different interventionprograms can be attributed to the observation that differentneuro-physiologic and -motor functions mature at different rates andtimes. In fact, the efficacy of a particular type of intervention maydepend on the particular developmental stage an infant is at when thatintervention is offered (as there are evidence that differentphysiologic functions are more receptive to “change” at specific times).

The aforementioned decision algorithms and methods of data analyses canbe performed using the previously-described “smart” baby bottle system.

Table 11 shows the experimental data from Lau & Smith [23], showing theaverage (mean) values; standard deviation and Coefficient of Variation(COV)=[(SD/mean)*100], for a range of Gestational Ages from 21-36 weeks(n=66 infants), with the study being done at the first oral feedingexperience. COV is a measure of the variability relative to the mean ofthe subjects' respective outcomes

TABLE 11 Experimental Values of OT, PRO, and RT from Lau [23] for arange of Gestational Ages from 21-41 weeks (n = 89 infants), study doneat first oral feeding experience. OFS OT (%)* PRO₅(%) RT₂₀ (ml/min)level [% COV]† [% COV] [% COV] 1 30.3 ± 23.6 [78%] 12.5 ± 7.3 [58%] 0.6± 0.4 [67%] 2 84.8 ± 16.5 [20%] 23.1 ± 3.6 [16%] 1.9 ± 0.3 [16%] 3 77.9± 21.1 [27%] 47.3 ± 20.2 [43%] 1.0 ± 0.2 [20%] 4 96.3 ± 12.3 [13%] 64.4± 22.8 [35%] 2.6 ± 1.0 [39%] *mean ± SD †[% Coefficient of Variation]

FIG. 22 shows the range of Overall Transfer, OT (%) as a function of OFSlevel (also shown in Table 11 [23]. Here, endurance is described by analternative measure, i.e., OT (Overall Transfer, %), where OT is definedby eq. (14) as:

OT=total volume taken at 20 minutes/V _(prescribed)×100(in %)  (14)

Here, we see from Lau & Smith [23] that OT may range between 0% to 55%for OFS level 1; 68% to 100% for OFS level 2; 68% to 99% for OFS level3; and 80% to 100% for OFS level 4.

FIG. 23 shows a chart of infant birth weight (Kg) versus Gestational Age(weeks), for a variety of percentiles commonly used in NICUs. Femalesand Male infants have basically the same set of curves.

Sensor Systems

FIG. 16 shows a schematic perspective view of a smart infant feedingbottle system communicating wirelessly with a smart device (e.g., smartphone, tablet, personal computer, or desktop data processing box). Sucha system 10 is also referred to as an Oral Motor Kinetics (OMK)monitoring system 10, where the OMK system comprises an infant feedingbottle 12 and a battery-powered sensor module 14 that can communicatewirelessly with a smart device 16 via a standardized Bluetooth® type ofcommunications protocol. Sensor module 14 is removable, and can bedisposed inside of bottle 12, or attached to the outside of the bottle.Sensor module 14 can also be disposed at the bottom of the bottle 12(not illustrated), which would be useful for weighing the contents ofliquid when the bottle is oriented vertically, or for measuring theheight of the liquid column above the bottom using an ultrasonic probeor laser optical fiber(s) oriented along the length of the bottle.Additional details of the sensing elements and sensor instrumentationmodules are contained in pending U.S. patent application Ser. No.14/416,039 to C. Lau, “Systems for Monitoring Infant Oral Motor KineticsDuring Nutritive and Non-Nutritive Feeding”, filed Jan. 20, 2015, whichis incorporated herein by reference in its entirety. In thisapplication, systems and methods are disclosed for: (1) using aminiature pressure transducer mounted near the nipple's tip to monitorthe intraoral pressure pulse during an individual suck, and (2) using apair of pressure transducers mounted front-to-back on the sidewall ofthe nipple to monitor the speed and intensity of an infant's tongue whenstripping the nipple (which relates to the expression component ofsucking) during an individual suck. A feeding bottle with such a set ofpressure transducers is called an “OMK bottle” (Oral Motor KineticsMonitoring System). Pressure transducers can also be mounted on apacifier, to make an “OMK Pacifier”; or mounted on a glove, to make an“OMK Glove”.

The sensor module 14 can have sensors that measure pressure (mm Hg), andalso the fluid flow rate (ml/min) through the nipple, among otherparameters (temperature, etc.). The module's means for measuring aninstantaneous fluid flow rate (“flow rate sensor”) can utilize orcomprise any of a wide variety of methods, devices, and structures thatmeasure/respond to a variety of physical properties of a moving fluid(e.g., velocity, and, hence, volumetric or mass flow rate; pressure;density; etc.), including, but not limited to: airflow sensor, pressuredifferential or pressure drop across a flow discontinuity or restriction(e.g., a Venturi section, calibrated orifice plate), ultrasonictechniques, thermal properties technique (e.g., Resistance TemperatureDetectors (RTD) thermistor, hot-wire technique, thermal flow sensor),MEMS micro flow sensor, electrochemical techniques (electrolytes,electrical admittance, “Lab-on-a-Chip”), MEMS Coriolis-effect flowmeter(resonant tube), semiconductor field effect, Particle Image Velocimetry(PIV), ultrasonic flow detectors, and flow-based laser or opticaltechniques, as described below. The volume of liquid (bolus, in ml)passing through the flow sensor as a function of time can be calculatedby integrating over time the instantaneous measured flow rate (ml/s).The time period for integration can equal, for example, the duration ofthe single suck; or it can be a longer fixed duration (e.g., a 1 minuteor 5 minute time period).

A first class of flow rate sensors comprises one or more sensingelements that are integrated with or reside within the nipple itself(bottle nipple or nipple shield). With the use of miniature/micro-sizedtransducers (e.g., micro-pressure transducers) and MEMS manufacturingtechniques, it is possible to fabricate fluid flow sensors that aresmall enough to fit inside a nipple, or even inserted into the nipple'sexit hole. This is particularly useful, because the fluid flowproperties (e.g., velocity, density, mass flow rate, volumetric flowrate) are preferably measured right at the point where the fluid leavesthe nipple (i.e., at or near the nipple exit hole).

A second class of flow rate sensors comprise one or more sensingelements and associated electronics contained inside a stand-alone flowrate module that is separate from the nipple, and is positionedsomewhere in-between the fluid reservoir (i.e., body of feeding bottle)and the nipple (e.g., in the neck region, or attached to the side of thebottle on the outside of the bottle). Preferably, the flow rate modulecan measure, as a function of time, the instantaneous velocity orvolumetric (or mass) flow rate of fluid flowing into (or out of) theinterior volume/space of the nipple. Allowing for changes in theinternal volume of the nipple when compressed during expression by thetongue, the flow rate module should be able to measure negative fluidvelocities (i.e., milk travelling in the opposite/backwards direction).Likewise, any numerical integration algorithm used to calculate thebolus volume per suck should be able to account for some period of timeduring a suck when the fluid velocity may be negative.

The flow rate module can utilize any of the wide variety (presentedearlier) of methods, devices, and structures that are capable ofmeasuring properties of a fluid in motion (and, hence, volumetric ormass flow rate), including, but not limited to: pressuredifferential/drop across a flow discontinuity/restriction (e.g., aVenturi section, calibrated orifice (AP), ultrasonic, thermal flowtechnique (e.g., RTD thermistor, hot-wire technique), MEMSmicromachines, electrochemical techniques (electrolytes, electricaladmittance, Lab-on-a-Chip), MEMS Coriolis-effect flowmeter (resonanttube), semiconductor field effect, Particle Image Velocimetry (PIV),ultrasonic, and flow-based laser/optical techniques.

A stand-alone flow rate module can have a generally cylindrical shape,and comprises at least one flow channel connecting a back end to a frontend for transferring fluid from the bottle to the nipple. Thestand-alone module can also comprise a flow rate sensing means formeasuring the fluid's velocity and/or flow rate inside the at least oneflow channel. The flow channel can have a necked-down or compressed(smaller-diameter) region with a higher fluid velocity where pressuredrop measurements are made with, e.g., a pair of micro-pressuretransducers. The flow rate module can optionally comprise electronicmeans for wirelessly transmitting the measured and/or transformed datato a remote receiver (e.g., a laptop computer, a smart phone, ortablet).

FIGS. 17A, 18A, 19A illustrate cross-sectional plan exploded views ofdifferent examples of integrating a self-contained, stand-alone sensormodule 14 into a feeding bottle 12 using various types of elongated neckpieces 16.

FIG. 17A shows a cross-section, exploded view of an embodiment of a flowrate module for an OMK system, according to the present invention. FIG.17B shows a cross-section view of the assembled components. An elongatedcrown ring 18 screws onto the neck 13 of the bottle 12, therebycompressing the nipple 17, the flow rate module 14, and an O-ring seal15, against the flat end 11 of the bottle's neck.

FIG. 18A shows a cross-section, exploded view of another embodiment of aflow rate module for an OMK system. The flow rate module 14 sits insideof transition piece/adaptor 24 that has internal screw threads 20 at theback end, which mates with the bottle's external threads 13. Adaptorpiece 24 has external screw threads 22 at the front end, which mates tothe nipple 17 (held by the crown ring 18). FIG. 18B shows across-section view of the assembled components.

FIG. 19A shows a cross-section, exploded view of another embodiment of aflow rate module for an OMK system. The flow rate module 14 has anintegral circular flange 19 at the front end that mates with the nipple17 (held by the crown ring 18). The flow rate module 14 has a slightlysmaller outer diameter than the inner diameter of the bottle's neck 13,which allows the flow rate module to slip inside of the bottle's neck.An O-ring seal 15 is disposed in-between the module's circular flange 19and the flat end 11 of the bottle's neck 13. FIG. 19-B shows theassembled components, which is a very compact assembly.

Other techniques can be used, in addition to, or in place of, astand-alone or nipple-integrated flow rate sensor module orinstrumentation device. For example, the change in weight of liquidinside the reservoir (bottle) can be measured before and after a singlesuck, to get the bolus volume per suck. Or, the change in height of theliquid column inside the reservoir (bottle) can be measured, with thedifference being proportional to the volume (bolus) of liquid lostduring a single suck. The change in weight (ΔW) can be measured by usinga sensitive pressure transducer located at the bottom of the bottle tomeasure small changes in pressure (weight of the fluid above thepressure transducer) when liquid is removed from the bottle duringfeeding.

Alternatively, the change in internal air pressure (increase in vacuumlevel) inside of a sealed bottle (i.e., with no anti-vacuum valve) canbe measured with a sensitive pressure transducer placed at or near thetop of the bottle. The removal of a bolus of liquid during a single suckcreates an incremental change in the vacuum air pressure level (via therelationship Pressure×Volume=constant, at constant temperature), whichcan be measured, in real-time, by a pressure transducer. Once aparticular bottle's geometry has been calibrated (and assuming a bottlewith a constant cross-section along it's length), then the drop ininternal air pressure measured by the pressure transducer, in real-time,will correlate directly to the volume of liquid removed, in real-time,from the nipple.

FIG. 20 shows a schematic cutaway view of an example of a micro-sensorprinted circuit board assembly for use inside of an infant feedingbottle (cover removed for clarity). FIG. 20 shows an instrumented nipple60 comprising a compact, miniaturized, integrated wirelessinstrumentation module 62 that fits snugly into the base of a standardnipple 17. The wireless module 62 can comprise one or more of thefollowing components: a flow rate sensor 50, pressure transducers 31,32, 33 and electrical leads to the module, microprocessor 36, battery42, transmitter 38, antenna 40, and mounting plate 54. The wireless IM62 can transmit data via, for example, Bluetooth®, to a BioPac® datacollection unit 66, an iPad® or iPhone® smart phone/tablet 66, or laptopcomputer, etc. A flexible metal bellows 48 can be used to permit flexing(bending) of a tube 46 connecting the flow rate sensor 50 with the exithole 56 at the nipple's tip.

The flow rate sensor 50 can comprise a pair of pressure transducersarranged to measure a pressure drop along the flow channel 44. Thepressure transducer can be a pair of laser fiber optic pressure sensorscan be, for example, a model No. OPP-M25, manufactured by OpSens, Inc.,in Quebec, Canada (www.opsens.com). This model has an outer diameter ofthe sensing head of 0.25 mm (250 microns), a pressure range of −50 to+300 mm Hg, a precision of +/−2 mm Hg, and a resolution of 0.5 mm Hg.OpSens also makes a larger fiber optic pressure sensor, OPP-M40, with a0.4 mm (400 microns) OD of the sensing head. The smaller model, OPP-M25,is the smallest MEMS based optical pressure sensor available on themarket today, and is used in a wide variety of medical applications,including: cardiovascular, intracranial, intrauterine, intraocular,intervertebral disc, urodynamic, and compartment pressure measurements.An optical sensor is immune to interference from radio frequency (RF)fields, magnetic resonance imaging (MRI) fields, and electromagneticradiation from electro-surgery tools.

An instrumentation module (i.e., sensor module) can be used with anytype of infant feeding bottle. Optionally, such a module can be usedwith an “Optima” type of feeding bottle, which is described in moredetail in pending U.S. patent application Ser. No. 14/549,519 to C. Lau,et. al, “Self-Paced Ergonomic Feeding Bottle”, filed Nov. 20, 2014 whichis incorporated herein by reference in its entirety.

FIG. 21A shows a cross-sectional view of a “self-paced” ergonomicfeeding bottle, according to the patent application mentioned above.Self-paced bottle 12 comprises a open air vent hole 126; a straightspine segment 130 running down along the upper outside of the bottle; arecessed thumb grip section 152; an overall ergonomically-shaped bottomside profile of the bottle which allows the bottle to rest comfortablyin an open hand without requiring a rigid grip; and a plurality ofvisual and tactile, raised anti-drip markers 150 which serve to guidethe caregiver in holding the bottle at the appropriate angle withrespect to the horizon, depending on the amount of formula remaining inthe bottle, which prevents the buildup of hydrostatic pressure duringfeeding and stops unnecessary dripping.

FIGS. 21B and 21C show isometric views of the same self-paced ergonomicfeeding bottle, illustrating how the bottle is well-balanced and how itrests comfortably in an open hand with minimal gripping strengthrequired. The present invention can use this type of feeding bottle.

FIG. 24 shows a chart detailing the components of an Advanced FeedingDevice, according to the present invention. The Advanced Feeding Device(AFD) comprises three main components: a baby (infant feeding) bottle,an instrumentation/sensing (monitor) module, and a data managementsoftware application. The baby bottle mates to the monitor module. Themonitor module (i.e., instrumentation/sensor module) can have thefollowing functions: (1) it captures feeding data; (2) it displayscurrent feeding performance; (3) it provides an alarm when feedingperformance drops below a safe threshold; and (4) it stores andtransmits feeding data to the software application, which can reside ona remote device, such as an iPad®, iPhone® or desktop computer. The datamanagement software application can have the following functions: (1) itrecords feeding data history; (2) it displays the history; (3) itprovides analysis of progress and trends over time; (4) and it cantransmit feeding data to clinical experts and EMR (electronic medicalrecord) systems.

A detailed minute by minute feeding history can be collected, alongsidewith the heart rate, blood pressure and other vital sign histories.Vital signs make up what is commonly known as the patient's “Chart”.Hospitals could add the feeding history to the Chart for the good reasonthat baby health events frequently tie in to feeding, so that it helpsdiagnosis. The method is to upload the data in a standard format definedby the hospital system and according to HIPAA rules. Secondly, we couldhelp by sending data to a doctor or therapist from the smart device APPto their system for review. The smart application sees signs of trouble,arranges for a consultation, and sends data.

Air Flow Rate Sensor

In a preferred embodiment, the amount of air flowing into a bottle withan open air vent can be measured (i.e., by a micro-sized differentialpressure measurement or thermal-response flow sensor technique) and setequal to the change in liquid volume exiting the bottle through thenipple (assuming that the inflowing air is essentially incompressible,which is reasonable since the temperature and pressure changes are verysmall inside and outside of the bottle). A similar technique was used byJain, et. al. [29], which used a large (non-miniaturized) air flow ratedetector unit.

Alternatively, the volumetric rate of incoming air flow can bedetermined by measuring the change in temperature of an electricallyresistively-heated strip or thin film of deposited metal or wiresuspended in the stream of air (or, by measuring the power required tomaintain a constant temperature in such a heated strip or wire ofmetal). This is called a micro thermal flow rate sensor, and it has anoutput signal that changes linearly with corresponding changes in thevelocity of fluid flowing through/over the thermal flow sensor. Becausethe metal strip/film is very thin (typically it is manufactured usingMEMS-based technology), it has a very fast thermal response rate (e.g.,1-10 ms response time), and can record very fast changes in fluidvelocity (air or liquid) over time. This would allow detailedmeasurement of the flow velocities as a function of time during ansingle, individual suck by the infant (ml/sec), assuming that the datacollection rate is sufficiently fast to catch the transient velocitypulse (e.g., greater than 10 Hz collection rate).

FIG. 25 shows a side cross-section view of an example of an air flowrate sensor disposed inside of an instrumentation module that is mountedto the outside of the bottle, on the bottle's sidewall. FIG. 26 shows aside, cross-section, exploded view of the example shown in FIG. 25.Module 108 comprises a hollow plastic case (rectangular box 110) thatencases the air flow sensor unit 138, flow tube 114, and associatedelectronics, battery, etc. Case 110 is removably attached to the upperside (spine 130) of bottle 12. Module 108 can be attached by any numberof well-known ways, including plastic/elastomeric latches, screws,magnets, sliding rails, rotating latches, elastic members, etc. Whenliquid is drawn out through the nipple by the infant during feeding,module 110 measures the volumetric rate of replacement air flowing intothe module through entrance aperture 112, passing through flow tube 114,past flow rate sensor unit 138, and finally exiting out of module 110through exit aperture 124. The exiting air continues flowing throughanti-vacuum valve 128, eventually dumping into the upper, open internalvolume 132 of bottle 12, where it exactly replaces the volume of liquiddispensed/taken through the nipple during feeding. The sensor signalsgenerated by flow rate sensor unit 138 are passed on to circuit board142, which contains a microprocessor unit (MCU) and other associatedelectronics for converting the sensor's output to a digital data stream,which is then transmitted wirelessly 146 to a remote device, such as aiPad® or other type of remote computer (not shown) for analysis anddisplay. Note that bottle 12 can be used as a regular feeding bottlewhen instrumentation module 110 is removed. The volume of fluid taken,V(t) can be easily calculated by integrating the measured rate ofvolumetric flow over a period of time.

FIG. 27 shows a cross-section view of another example of an air flowrate sensor chip disposed inside of an instrumentation module that ismounted to the outside wall of the bottle, on the bottle's upper side.Module 108 comprises a hollow case 110 with an entrance aperture 112 andexit aperture 124, which are fluidically connected to each other by tube114 disposed within case 110. During feeding, air flows into theentrance aperture 112 of case 110. A coarse, replaceable particle filter113 is provided in the flowstream near the entrance aperture 112 toscreen out large particulates, dust, etc. The coarse filter can have apore size of about 5-10 microns, for example. Tube 114 can be made ofmedical grade silicone or polyethylene, for example, and can have aninner diameter of approximately ⅛″ (ranging from 1/16″ to ¼″). Tube 114is held securely to the sidewall of case 110 using a plurality ofintegrally-molded web support brackets 121, 121′, 121″ that the tubingsnaps into. Module 110 further comprises a pair of hydrophobic, finedisc filters: upstream filter 117 and downstream filter 119, which areheld in place with upstream filter housing 116 and downstream filterhousing 120, respectively. The pore size of the fine filters is selectedto pass air, but stop water or formula from passing through the filter.For example, the pore size can be 2 microns. The fine filters can bemade of a hydrophobic material, preferably transparent, so that visualdetermination of bacterial contamination can be made. Fine filters 117and 119 prevent liquid (formula or water) from entering the micro-sizedair flow passages in air flow rate sensor chip 138.

FIG. 27 further shows a calibrated flow orifice plate (disc) 118 heldinside the flow tubing 114 by orifice holder 115. The purpose of orificeplate 118 is to create a defined pressure difference (pressure drop,ΔP=P₁-P₂)) between the upstream location (P₁) and the downstreamlocation (P₂) on either side of the orifice. The diameter of the hole inthe orifice plate 118 can be in the range of 0.010″ to 0.020″ diameter.Short segments of bypass tubing 134 and 136 fluidically connect pressuretaps at upstream and downstream locations (P₁, P₂) of tube 114 (aboveand below the orifice plate 118), to the input and outlet ports ofairflow rate sensor chip 138, respectively. Airflow rate sensor chip 138is a micro/MEMS thermal flow sensor comprising a thin-metallic filmsensing element 140 (e.g., thin platinum film) that isresistively-heated by electricity. Air flowing across the surface of thesensing element 140 is heated, and the difference in temperature of thestream of air before and after (upstream and downstream of) the heatingelement 140 is measured, which provides a signal that is directlyproportional to the velocity of the air flow, which is also proportionalto the pressure drop ΔP across the inlet/outlet ports of sensor chip138. Knowing the velocity of air flow, the volumetric flow rate can beeasily calculated via the density of air and cross-sectional area of theflow. Alternatively, it is known that the volumetric flow rate for aprecision orifice of known diameter is directly proportional to thesquare root of the pressure drop across the orifice, ΔP. Once the systemhas been calibrated, the constant of proportionality can be programmedinto the data analysis program, and the air flow rate calculated (sccm).Once the air flow rate is known, at any point in time, the equivalentrate of liquid (formula) flowing out of the nipple can be calculated byusing the ratio of density between air and liquid (formula). Theelectrical output of sensor chip 138 is provided to electronics circuitboard 142, which contains a microprocessor control unit (MCU),associated electronics, and transmission circuitry for transmitting awireless data signal 146. Rechargeable batteries 144 provide electricpower to the module, and an input/output port is provided to provide forprogramming/software changes and data input/output.

Not shown in FIG. 27 are optional design features: LED power/systemstatus lights; USB interface port for holding, e.g., a flash drive; ormicro-USB programming interface port; ON/OFF switch; and LEDdata/message display screen; and piezoelectric loudspeaker; chargingcord plug. Batteries 144 can be recharged from a charging station usinga wireless inductive charging technique and induction coils embeddedwithin the module 110. Module 110 can optionally comprise a tip/tiltMEMS sensor for sensing the angle of tilt of the module, which can beused to turn the unit ON/OFF, depending upon it's orientation. Module110 can optionally comprise an optical fiber interface port fordownloading digital data optically from the module to memory storagelocated in a charging station, so that data history is automaticallydownloaded into the charged station when the module is charged.

FIG. 28-30 show isometric views of another example of an air flow ratesensor disposed inside of an instrumentation module that is mounted tothe outside of a feeding bottle, mounted on the bottle's sidewall.Module 108 comprises a case 110 with entrance aperture 112; airflow ratesensor chip 138; electronic circuit board 142; air flow chambers 114;and exit aperture 128.

Prototype Sensor Design, Fabrication and Initial Testing

The maximum air flow that the sensor should see should be in the rangeof 30 sccm. Accuracy of 5% or better is preferred. Due to the desirablerequirements that formula contamination not be permitted in any part ofthe sensor assembly, it is clear that the small sensing channels andelements typically associated with low pressure flows (e.g., in the 30sccm range) should not be exposed to the formula. This is because theycannot be easily decontaminated, sterilized, or serviced(disassembly/reassembly). The implication is that the volumetric flowrate measurement must be done indirectly without contact with the liquidformula itself. Measurement approaches are thus directed to measuringthe amount of air volume that enters the bottle in order to maintain astable atmospheric pressure equilibrium when the same volume of liquidis removed from the bottle by the infant. The fluid flow exiting fromthe bottle should be equivalent to the air flow into the bottle(assuming quasi-static conditions), as guaranteed by the ideal gas law,PV=nRT. Instead of measuring the fluid flow directly, we can measure theair that must come into fill the volume of the fluid that has left thebottle.

There are many air flow sensors available in the marketplace. Most arenot commercially available in miniature packages suitable for use in thevery limited physical space available in the bottle's spine. However, aMEMS-based technology from SensorTechnics, Inc. was identified that wassuitable. After some study, it was determined that the “LDE” series ofdifferential pressure sensors could be used with a calibrated bypassorifice as a suitable flow sensor covering range of 0-30 sccm. Thissensor has a low power requirement, small size, robust mechanicalproperties, and an efficient microprocessor interface, along withexcellent sensitivity and range. The model “LDES050U 50 Pa” full-scalesensor was chosen for use in the proof-of-principle demonstrationprototype. SensorTechnics can produce custom versions (smaller packagingand plumbing connections—possibly integrated with other components as amicrofluidic assembly).

Orifice sizing calculations were performed that indicated an orificesize of 0.010″ to 0.020″ diameter for a 25 Pa drop across the sensor.The prototype actually used a 0.020″ diameter orifice with a 50 Pasensor, with resulting flow resolution of approximately 0.01 sccm and afull scale of about 100 sccm. Precision orifices of several sizes weresourced, with convenient barb fittings, to permit exploration of theparameter space.

In operation, flow rate measurements will be made at about 10 Hz. Ateach sampling interval the flow rate, along with a timestamp, will bestored in NVRAM (a flash drive has been used to some extent on theproof-of-principle unit). Algorithms specified herein will be on the MCUto look at this data stream in real-time to generate simple feedbacksignals to the user. It is anticipated that, if available, a GPSlocation and timestamp can be stored along with the data for eachfeeding.

Note that the flow rate scaling using pressure drop across an orifice toflow through the orifice requires a square-root operation (note:volumetric air flow rate is proportional to the square root of thepressure drop, P₁-P₂, across the orifice. This can be expensive in termsof computational resources and power, so it will need to be carefullyimplemented using either lookup tables or an approximation technique. Astrongly suggested method is via CORDIC rotations. In theproof-of-principle/prototype unit this was done using standardfloating-point calculations.

A means is required to keep the formula out of the sensor itself whenthe bottle is not in use (such as when lying in the bottom of a baby bagduring a car trip). The fluid must be also kept out of the sensorplumbing during a shock event (accidentally dropping the bottle),inversion, or other unfortunate circumstance. A means should be providedfor the user to visually inspect the state of the plumbing and sensor,and if contaminated it should be disposed of and replaced easily.

To accomplish this, several concepts were employed, as shown in thefollowing figures. Several layers of defense against infiltration of theformula into the sensor can be used:

(1) Use the existing silicone slit check valve (anti-vacuum valve 128)to greatly impede the backflow of formula from the bottle back into theinstrumentation module 110 (sensor assembly). The cracking pressure(first leakage of fluid through the valve) of the slit valve is about0.1 inches of H₂O, i.e., very low. Commercial micro-checkvalves werefound not to come even close to approaching the performance or price ofthe silicon slit valve, so it was retained. This is convenient, as wellbecause it enables the same bottle to be used with or without the smartfeeding module. Some mechanical work will be required to reliablyconnect the checkvalve to the bottle and the sensor plumbing. Twist-lockmechanisms such as a Luer-Lock are very mature, reliable, and costeffective and should be considered for use in later design work. Theinitial work was done with an interference fit between silicone tubingand the ID of the checkvalve.

(2) Use an inlet labyrinth consisting of small volumes separated byorifices as means to impede the flow of fluid that has traveled past theslit checkvalve. For the proof-of-principle unit, a small transparentacrylic assembly was designed and fabricated with two internal volumesseparated by a 0.035″ orifice. The idea is that after filling the firstvolume, fluid would be restricted by the small orifice and must stillfill the second volume before getting further into the sensor. Theassembly was easily inspected visually for the presence ofcontamination. In production, a similar type arrangement could easily beincluded in a small integrated microfluidic assembly, along with thesensor and other components. The pressure drop across this assembly wasfound to be insignificant at the flow rates required. However, it wasfound that over a relatively short time (few tens of minutes) water wasable to get through the labyrinth, rendering this approach ineffective.

(3) A hydrophobic pore filter can be interposed between the inletlabyrinth and the flow sensor. If the pore size is below about 0.2microns, then this filter can also desirably trap bacteria that mightflow from into the bottle from the outside air (a sterilizing filter), auseful property. Practically, the filter must not exhibit more thanabout 0.25 inch H₂O pressure drop at 30 sccm flow. This is a seriousissue for small pore size filters, forcing the face area of the filterto be large—easily 5 or more sq. cm. This could be accommodated in themicrofluidic assembly, but for the proof-of-principle unit this was doneusing 25 mm dia Luer-Lock disc filters.

At the very low backpressures encountered in this device, these filterswere found to completely block the flow of water. Unfortunately therewas also significant pressure drop, in the range of 2 in H₂O. Pressuredrop data are extremely rare for these devices and is not commonlysupplied by the manufacturers. To avoid having to go to very large facearea, we should go with larger pore size filters in the next phase,likely 2 microns or so, which are still hydrophobic. We will no longerhave sterile air flowing in, but that is not a critical requirement. Wewill need to re-verify the fluid blocking property at that time.

These filters can be transparent for ease of inspection, and should beeasily removable and replaced (disposable) at an economic price if oneshould be determined to be contaminated. These filters can be had asCOTS units in large quantity for about $0.30, with Luer-Lock fittings.With appropriate design (possibly including custom inlet-outletgeometry) such a filter could be an easily replacement part of thebottle spine module, as required.

In summary, it was found that the silicone slit micro-checkvalve inconjunction with an appropriately sized pore-disc filter(s) can provideadequate protection of the sensor from fluid in the bottle. Optionally,a pair of filter discs can be placed on either side of the flow ratesensor, i.e., both upstream and downstream of the sensor, to protect itfrom sources of liquid entering the instrumentation module from eitherdirection.

The SensorTechnics LDE series sensors are surprisingly robust to thepresence of particulates in the air. The orifice used as a bypass isnot, unfortunately, and will require a second filter be placed upstreamof the sensor assembly to prevent larger dust, lint, or other particlesin the environment from entering the sensor assembly. This filter can bea large pore filter, easily 5 microns or so, and will not present apressure drop issue even if used in smaller diameter formats (16 mm orso). This coarse filter is not required to have hydrophobic properties.These filters are readily available, but may require custom inlet andoutlet fitting geometries for the production unit, unless integrateddirectly into the microfluidic assembly.

The entire sensor assembly is integrated in the form of a module thatattaches (e.g., snaps/latches) to the bottle, effectively forming theupper spine of the bottle. This implies a maximum radial thickness ofaround 1 cm, a width of around 3 cm, and a length of around 10 cm. Sucha package, or closely related constant-volume scalings of it, forms aconveniently sized unit that should present an attractive appearancewhen attached to the bottle.

Initial considerations indicate that a rectangular 850 maH LiPo batterypack (3 cm×8 cm×0.6 cm) should provide sufficient power for the module.This should leave enough space for a small custom PCB to hold the MCU,interface circuits, sensor circuits, and user indicators, along with themicrofluidic assembly containing the sensors, filters, micro-checkvalve,and the fittings for connection to the bottle.

This assembly will likely need to be nearly fully encapsulated or pottedfor mechanical robustness and sealing against the inevitable multiplewater submersion events the device will see in a typical household.Potting eliminates the requirement for a housing or an internalframe/bracket assembly. Ergonomic features can be molded into thesurface of the final article. For large production, individual pottingmay be too time-consuming and this issue may need to be revisited.

The spine module is expected to operate for a total duration ofapproximately 6-8 hours during the course of a day. Given that the unitwill be a fully encapsulated module, the battery is required to be ofthe rechargeable type. The best power density in COTS units today isprovided by Lithium-Polymer cells (LiPo). These units require specialcharging and protection circuits for consumer use, however. Fortunately,there are a number of suppliers of these devices, complete with onboardprotection circuitry.

An initial power budget indicated that an 850 maH battery should besufficient to operate the module for the required 8 hours, subject toreasonable power consumption by the user indicators (Note: extra LEDs,light ring, etc.—have not been addressed at this time).

A special consideration established early on is that the unit should nothave any form of electrodes exposed on the surface of the module. Thesepresent a reliability and surface contamination issue. Battery chargingmust be non-contact. We evaluated a simple proximity-inductive chargingapproach and found that with two coils approximately 3 cm in diameter,we were able to transfer sufficient power to recharge the battery in afew hours at coil separations up to about 8 mm. This provides sufficientdesign leeway to develop a convenient charging cradle for the module(potentially with a bottle attached).

LiPo batteries also require special charging procedures. Severalmanufacturers now provide integrated circuits specifically for this taskthat can easily be designed into the custom spine PCB. Furthermore, weanticipate that we will require a boost converter to bring the LiPovoltage (3.7V) up to 5V to operate the sensors. Devices for this taskare also readily available and easily integrated.

A key aspect to maximizing battery life is minimization of standbyoperating current. To accomplish this task, we anticipate using embeddedpower control circuits to remove power from all non-essential devicesduring each phase of operation. This is done using control lines fromthe MCU to individual FET switches on the power line to the devices(unless the devices have built-in shutdown pins). The MCU itself willhave a great deal of built-in power management functionality and will beoperated in low power sleep mode when the bottle is not in use. Thisapproach effectively has the battery running at near leakage-currentlevels when the bottle is idle.

To bring the bottle to life, we can use passive orientation sensors todetect the transition of the bottle from any orientation into thefeeding orientation. The feeding orientation is nearly horizontal (towithin about +/−15 degrees) with the spine of the bottle on top. Wefound that this orientation can be easily detected passively using apair of tilt switches that monitor the axial and azimuthal orientationof the bottle. When this condition is sensed, the MCU will be broughtout of sleep mode, immediately initialize the sensors, and beingmonitoring and recording the flow through the bottle. A timer will alsobe triggered to turn the bottle off after one hour, or after 15 minuteswithout any further indication of motion.

This approach allows the bottle to remain in an extremely low powerstate for long periods of time until the user wants to put it intoservice, and at that point the transition to operation is completelytransparent to the user who is unaware of the process.

Cost is a primary concern in any consumer device. For this unit, weanticipate needing to keep the cost of the sensor and spine board downto a total of less than $50. The most expensive individual part on thisunit is the LDE sensor, and the most expensive subassembly is expectedto be the integrated microfluidic assembly that carries themicro-checkvalve, inlet hydrophobic filter, sensor, orifice, particulatefilter, and connection fittings. With suitable large volumes it isexpected that this assembly can be procured for around $27. Theelectronics and battery will be about another $16. The customerreplacement parts (inlet filter, micro-checkvalve, and connectionfitting) should be integrated into a single disposable component, whichshould be producible for less than $1.50 ea.

It is anticipated that the SmartBottle will normally be kept in awall-mounted cradle for storage and wireless battery charging. Thecradle has greatly reduced constraints on power and size and can easilybe operated using a wall-mounted low voltage power supply, similar to awireless telephone. The cradle is expected to incorporate a batterycharge state indicator.

The cradle is also expected to serve as a hub for collecting the flowrate histories from the bottle. We anticipate implementing an opticaldata link between an MCU in the cradle and the spine board MCU. Theoptical transmitter and receiver on both sides can be coupled via shorttransparent plastic light guides to an area hidden from view when thebottle is in the cradle. With suitable arrangement of the light guidesthere should be no issue with alignment of the bottle to the cradle orpresence of surface contaminants (easily remove with a damp cloth if itshould occur). The encapsulant on the spine module should fully seal thelight guides, so there should also be no opportunity for bacterialaccumulation in that area.

An initial survey of devices that might serve as a convenient opticaldata link revealed an IrDA device, Vishay TFBS4711, which canconveniently by driven from the MCU on each side of the data link. Weanticipate implementing a simple serial protocol using this device toretrieve and manage flow measurement data, usage statistics, batterylife, charge state information, and diagnostic information. These datacan be further analyzed by the cradle MCU or could be transmitted viaWi-Fi or other mechanism for further use by the user. This functionalitywas not investigated in this work as it is a well-developed body ofknowledge.

The proof-of-principle unit was assembled using an Arduino Uno equippedwith a GPS shield, flash drive shield, LCD shield (for immediateobservation of flow measurements), and a custom shield containing theLDE sensor circuitry. Firmware was developed to collect the data andeither store it on the flash drive or transmit via USB to the host PCfor capture into spreadsheets.

The plumbing was implemented using silicone tubing and barb fittings forthe orifice, a Luer-Lock pore-disc filter, the inlet labyrinth assembly,and a graduated dispensing bottle serving as a surrogate for the feedingbottle. A siphon tube was used to establish flow from the dispensingbottle, with the replacement air being pulled through the sensorassembly.

The following photographs (FIGS. 31-33) show the proof-of-principle testassembly used to take the initial experimental measurements.

The following sequence of photos (FIGS. 33-37) shows the use of thesiphon to simulate different extraction pressures from the surrogatebottle. Note that since the fluid is water, the pressure in inches ofwater (in H₂O) is simply given by the difference in height (in inches)between the nozzle on the surrogate bottle and the end of the siphontube (shown attached to an empty dispenser bottle for convenience).

Uniform Flow, Low Flow Rate

The data, shown in FIG. 38-39, were taken to show the measurement offlow when the siphon was set at a constant height, with the surrogatebottle allowed to empty during the run (which changes the heightdifferential). The data were collected at 1 sample per second (1 Hz)using a 0.025″ orifice and an LDES050UF6S (50 pa) sensor. The smallpositive transient is due to the cap being placed on the surrogatebottle. The following large negative transient is the siphon beingstarted. The upward slope on the pressure is due to the water level inthe surrogate bottle dropping during the run (as expected). Thesurrogate bottle was filled to 120 mL as measured using one of theoriginal Optima feeding bottles. The volume is not fully calibrated butis a representative indicator.

High Flow, Varying Rate and Extraction Pressure

For these data, shown in FIGS. 40-41, the flow rate was much higher andwas set up to simulate the time varying extraction pressure that mightbe applied by a feeding infant. The pressure was set to one of fourlevels by moving the end of siphon to different heights.

Here the steps in the integrated volume are visible as the flow ratechanges. The four pressure levels are also clearly visible (there arefour quantized levels seen). The integrated volume ceases to increase asthe surrogate bottle fully drains (incremental volume goes to zero).

The following chart, in FIG. 42, shows the raw 10 Hz pressure datacorresponding to the above charts. These data are filtered in real-timeon the Arduino to produce the incremental volume. The transients occuras the siphon hose is quickly moved from one level to another. Note thatthere is significant fine detail present that may be of interest inclinical work. All of these data is expected to be stored andtransmitted to the cradle for further processing in the productionunits.

In summary, regarding the prototype, the most critical areas of concernregarding design elements for the Optima SmartBottle have beeninvestigated. Sufficient information and data have been collected toindicate that the identified approaches will meet the requirements.There are yet other approaches that were not investigated in this work;they should be considered when doing the initial product design. Themost critical issue, that of flow sensing with very limited power andphysical space, appears to be handily addressed with the SensorTechnicsLDE device.

Alternative Sensor Means

Alternatively, the change in height (AH) of the liquid column inside thebottle can be measured by a laser beam liquid level sensing system, orby an ultrasonic liquid level sensing system, along with the appropriateelectronics and hardware/software data analysis equipment. To get moreaccurate measurements of change in height of the liquid column, thesystem can optionally include: 1) an anti-slosh structure inside thebottle (e.g., a bundle of straws or small diameter tubes, or a poroussponge, which damps unwanted waves/sloshing), and/or 2) a MEMS-basedhorizontal level detector/indicator mounted to the side of the bottle,for indicating when the bottle is being held vertically (via a buzzingsound, or via LED signal lights, or via a liquid crystal numeric displayindicating the bottle's tilt angle in degrees).

Using Integrated Chip (IC) semiconductor technology available today, itis possible to fabricate a compact, miniaturized, integrated wirelessinstrumentation module (IM) that fits snugly into/inside of the base ofa standard nipple, (or attached to the outside of a bottle) whichincorporates an integrated microprocessor, A/D converters, flow sensorand pressure transducer electronics, battery, transmitter, and antenna.

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What is claimed is:
 1. A smart feeding system for feeding a person witha nutrient liquid, and for assessing the person's oral feeding skills,comprising: (a) a smart feeding bottle; (b) sensor means for measuringone or more parameters of liquid ingested by a person during a feedingsession; and (c) a computer processing unit (CPU) programmed formonitoring and analyzing sensor data generated by the sensor means;wherein the CPU is programmed for calculating an Oral Feeding Skill(OFS) level by comparing the one or more parameters of liquid ingestedby the person during the feeding session to one or more preselectedcutoff values; and wherein an OFS scale defines a range of feedingperformance characteristics; and wherein the sensor means is containedwithin an instrumentation module that is disposed outside of the feedingbottle, and wherein the instrumentation module is removably attached toa sidewall of the feeding bottle.
 2. The smart feeding system of claim1, wherein the Oral Feeding Skills (OFS) level is calculated to be 1, 2,3, or 4, at any point in time during the feeding session, according tothe following OFS scale: OFS level=1 indicating Low oral feeding skillsand Low endurance; OFS level=2 indicating Low oral feeding skills andHigh endurance; OFS level=3 indicating High oral feeding skills and Lowendurance; and OFS level=4 indicating High oral feeding skills and Highendurance; and wherein the smart feeding system further comprises: (d)alphanumeric display means for notifying a caregiver to “STOP FEEDING”if OFS=1 at any point during the feeding session; (e) alphanumericdisplay means for notifying the caregiver of “INTERVENTION NEEDED” ifOFS=2 or 3 at any point during the feeding session; and (f) alphanumericdisplay means for notifying the caregiver to “CONTINUE FEEDING” if OFS=4at any point during the feeding session.
 3. The smart feeding system ofclaim 1, wherein the one or more parameters of liquid ingested by theperson is a volume, V(t), of liquid ingested over a period of time, t,measured from a start of feeding at t=0.
 4. The smart feeding system ofclaim 1, further comprising wireless communication means forcommunicating data wirelessly from the sensor means to a remotecomputing device that comprises said computer processing unit (CPU). 5.The smart feeding system of claim 1, wherein the one or more parametersof liquid ingested by the person is a volumetric flow rate, FR(t), ofingested liquid measured at a specific point in time, t.
 6. The smartfeeding system of claim 2, further comprising sound generating means fornotifying a caregiver with an audible message or sound containing statusinformation based on the calculated OFS level.
 7. (canceled)
 8. Thesmart feeding system of claim 1, wherein the CPU is programmed forcalculating two feeding performance parameters: (1) a Proficiencyparameter, PRO(5), in percent (%), that is equal to a percentage ofvolume (ml) of liquid ingested during the first 5 minutes of feedingdivided by a total volume (ml) of liquid that is initially prescribed,V_(prescribed); and (2) a Rate of Transfer parameter, RT(total), that isequal to an overall average flow rate of liquid transfer (ml/min)averaged over an entire duration of the feeding session, which is equalto a total volume of liquid ingested, V_(total), over the entire feedingsession divided by the total duration of the feeding session.
 9. Thesmart feeding system of claim 8, wherein the CPU is further programmedfor calculating the OFS level by performing the following logicalcomparisons at an end of a feeding session: (a) If PRO(5)≥PRO₅ andRT≥RT_(total) ml/min, then OFS=4; (b) If PRO(5)≥PRO₅ and RT<RT_(total)ml/min, then OFS=3; (c) If PRO(5)<PRO₅ and RT≥RT_(total) ml/min, thenOFS=2; and (d) If PRO(5)<PRO₅ and RT<RT_(total) ml/min, then OFS=1;wherein: PRO₅=30% and RT_(total)=1.5 ml/min, for infants with aGestational Age (GA) in the range of 25-33 weeks; PRO₅=40% andRT_(total)=1.5 ml/min, for infants with a Gestational Age (GA) in therange of 34-36 weeks; and PRO₅=50% and RT_(total)=3.0 ml/min, forinfants with a Gestational Age (GA) in the range of 37-42 weeks.
 10. Thesmart feeding system of claim 1, wherein the CPU is further programmedfor calculating an overall volumetric competency, defined as OT (OverallTransfer, %), which is equal to a total volume of liquid ingested by theperson during a feeding session, V_(total), divided by a prescribedinitial volume, V_(prescribed), with the ratio OT being expressed interms of a percentage (%).
 11. The smart feeding system of claim 1,wherein the CPU is further programmed for calculating a prescribedinitial volume, V_(prescribed), for a single feeding session, as afunction of an infant's weight, W (in Kg) and a number of feedingsessions per day, N, according to Eq (1):V _(prescribed) =C×W/N(ml/session)  (1) wherein: C=150 ml/Kg for infantsborn <34 weeks gestation, C=137.5 ml/Kg for infants born between 34 to36 weeks gestation, and C=124 ml/Kg for infants born between 37 to 42weeks gestation.
 12. The smart feeding system of claim 1, furthercomprising a weight scale for calculating the volume, V(t), of liquidtaken by the person as a function of time during the feeding session;wherein the CPU is programmed for converting measured changes in weightof the feeding bottle, over a period of time, into changes in volumeingested via the liquid's density (g/ml).
 13. The smart feeding systemof claim 1, wherein the CPU is further programmed for calculating anintegrated volume of fluid, V(t), ingested by the person, as a functionof time, by calculating an integral of the following quantity: ameasured instantaneous flow rate, FR(t), (ml/min) times a small timeincrement (dt), integrated over a period of time from t=0 to t=t,according to Eq. (2):V(t)=INTEGRAL_([t=0 to t]){FR(t)·dt}.  (2)
 14. (canceled)
 15. The smartfeeding system of claim 1, wherein the instrumentation module comprisesan inlet for admitting air; and an outlet in the instrumentation modulethat is in fluid communication with an open air vent hole disposed onthe bottle's sidewall.
 16. (canceled)
 17. The smart feeding system ofclaim 15, wherein the instrumentation module comprises a one-way,anti-vacuum valve in fluid communication with, and mounted in, thebottle's air vent hole; whereby any buildup of negative pressure insidethe bottle during feeding is prevented by allowing air to flow into thebottle through the one-way valve, while also preventing leakage of fluidin the opposite direction out through the one-way valve.
 18. The smartfeeding system of claim 1, wherein the feeding bottle comprises aself-paced, ergometrically-shaped bottle with a one-way, anti-vacuumvalve disposed in an air-vent hole disposed on a sidewall of the bottle;and further wherein the bottle or a nipple crown comprises one or moretactile or visual display markers for guiding a caregiver to tilt thebottle at an optimum angle such that a hydrostatic pressure within thebottle is substantially equal to zero during feeding.
 19. The smartfeeding system of claim 15, wherein the instrumentation module furthercomprises one or more filters capable of filtering out viruses ormicroorganisms present in a surrounding environment from a stream of airflowing into the instrumentation module during the feeding session. 20.A smart feeding system for feeding a person with a nutrient liquid, andfor assessing the person's oral feeding skills, comprising: (a) a smartfeeding bottle; (b) sensor means for measuring one or more parameters ofliquid ingested by a person during a feeding session; and (c) a computerprocessing unit (CPU) programmed for monitoring and analyzing sensordata generated by the sensor means; wherein the CPU is programmed forcalculating an Oral Feeding Skill (OFS) level by comparing the one ormore parameters of liquid ingested by the person during the feedingsession to one or more preselected cutoff values; wherein an OFS scaledefines a range of feeding performance characteristics; wherein an OFSscale defines a range of feeding performance characteristics; whereinthe Oral Feeding Skills (OFS) level is calculated to be 1, 2, 3, or 4,at any point in time during the feeding session, according to thefollowing OFS scale: OFS level=1 indicating Low oral feeding skills andLow endurance; OFS level=2 indicating Low oral feeding skills and Highendurance; OFS level=3 indicating High oral feeding skills and Lowendurance; and OFS level=4 indicating High oral feeding skills and Highendurance; and wherein the smart feeding system further comprises: (d)alphanumeric display means for notifying a caregiver to “STOP FEEDING”if OFS=1 at any point during the feeding session; (e) alphanumericdisplay means for notifying the caregiver of “INTERVENTION NEEDED” ifOFS=2 or 3 at any point during the feeding session; and (f) alphanumericdisplay means for notifying the caregiver to “CONTINUE FEEDING” if OFS=4at any point during the feeding session; wherein the sensor means isdisposed within a stand-alone, self-contained, battery-powered,wireless, removable instrumentation module disposed outside of thefeeding bottle and attached to a sidewall of the bottle; wherein theinstrumentation module comprises an inlet for admitting air, and anoutlet that is in fluid communication with an open air vent holedisposed on the bottle's sidewall; and wherein the instrumentationmodule further comprises one or more filters capable of filtering outviruses or microorganisms present in a surrounding environment from astream of air flowing into the instrumentation module during tge feedingsession.
 21. The smart feeding system of claim 4, wherein the remotedevice is selected from the group consisting of a smart phone, smarttablet, laptop, personal computer, and a dedicated desktop dataprocessing device. 22-26. (canceled)
 27. The smart feeding system ofclaim 15, wherein the computer processing unit (CPU) is contained withinthe instrumentation module.
 28. The smart feeding system of claim 27,further comprising wireless communication means for wirelesslycommunicating results data from the CPU to a remote device thatcomprises an graphical utility application for displaying (1) resultsabout the OFS level, and/or (2) results about sensor data.
 29. The smartfeeding system of claim 15, wherein the instrumentation module is astand-alone, self-contained, battery-powered, wireless module.
 30. Thesmart feeding system of claim 1, wherein the nutrient liquid is selectedfrom a group consisting of mothers' milk, infant formula, nutritionaldrinks, and water.
 31. A smart feeding system for feeding a person witha nutrient liquid, and for assessing the person's oral feeding skills,comprising: (a) a smart feeding bottle; (b) sensor means for measuringone or more parameters of liquid ingested by a person during a feedingsession; and (c) a computer processing unit (CPU) programmed formonitoring and analyzing sensor data generated by the sensor means;wherein the CPU is programmed for calculating an Oral Feeding Skill(OFS) level by comparing the one or more parameters of liquid ingestedby the person during the feeding session to one or more preselectedcutoff values; wherein an OFS scale defines a range of feedingperformance characteristics; and wherein the sensor means comprises anairflow rate sensor MEMS chip for measuring a flow rate (ml/min) of airpassing through an open air vent hole disposed in the sidewall of thefeeding bottle; and wherein a flow rate of liquid leaving the bottlethrough an attached nipple is equal to a flow rate of air flowing intothe open air vent hole during feeding.
 32. The smart feeding system ofclaim 31, wherein the sensor means is contained within aninstrumentation module that is disposed outside of the feeding bottle;and wherein the instrumentation module is removably attached to asidewall of the feeding bottle.
 33. The smart feeding system of claim32, further comprising a pair of filters disposed in the instrumentationmodule that are capable of filtering out viruses or microorganismspresent in a surrounding environment from a stream of air flowing intothe instrumentation module during the feeding session; wherein onefilter is located upstream of the airflow rate sensor MEMS chip, andanother filter is located downstream of the airflow rate sensor MEMSchip.
 34. The smart feeding system of claim 9, wherein the feedingduration is equal to 20 minutes; and RT_(total)=RT₂₀.
 35. The smartfeeding system of claim 8, wherein the CPU is further programmed forcalculating the OFS level by calculating every minute an average liquidflow rate, FR(t), based on measured sensor data, and concurrentlyperforming the following logical comparisons: (a) if FR(t)=0-4 ml/min,then setting OFS=1; (b) if FR(t)=5-9 ml/min, then setting OFS=2-3; and(c) if FR(t)>10 ml/min, then setting OFS=4; wherein an OFS level=1 isassociated with a display color “RED”, and a visual or audible indicatorprovided to a caregiver=“STOP FEEDING”; wherein an OFS level=2-3 isassociated with a display color “YELLOW”, and a visual or audibleindicator provided to a caregiver is “BE WATCHFUL”; wherein an OFSlevel=4 is associated with a display color “GREEN”, and a visual oraudible indicator provided to a caregiver is “GOOD FEEDING”.
 36. Thesmart feeding system of claim 10, wherein the CPU is further programmedfor calculating the OFS level by comparing the OT (Overall Transfer, %)to a scale according to the following logical comparisons: (a) OFS=1when 0≤OT≤13%; (b) OFS=2 when 13%<OT<60%; (c) OFS=3 when 60%<OT<90%; and(d) OFS=4 when 90%<OT≤100%.
 37. The smart feeding system of claim 8,wherein the CPU is further programmed for calculating the OFS level byperforming the following logical comparisons at a specific time=t afterstart of feeding, wherein time is measured in minutes: (a) if PRO(t)≥6·t(%), then OFS=3 or 4; wherein (i) if RT(total)≥1.5 ml/min, then OFS=4,and (ii) if RT(total)<1.5 ml/min, then OFS=3; (b) if PRO(t)<6·t (%),then OFS=1 or 2; wherein (i) if RT(total)≥1.5 ml/min, then OFS=2, and(ii) if RT(total)<1.5 ml/min, then OFS=1; (c) if PRO(t)<2·t (%), thenOFS=1.